As within so many other topics of history, the position and role of women in Zoroastrian societies is poorly attested, even by the standards of Zoroastrian sources. It remains a touchy subject to this day within Parsi communities, where as a rule, women are not allowed to marry outside the community. The result of this has been a relative and absolute decline in the size of Parsi communities, with many women leaving or declining to have children.

To look at the roots of Zoroastrianism, it is, like any other Indo-European religion, decidedly patriarchal. Ahura Mazda is male. Zoroaster is male. The messianic Saoshyants are yet-to-be-born sons of Zoroaster, whose seed has been miraculously preserved in Lake Hamun in Sistan. However, in its earliest sources it is not clearly misogynist in the way, for example, Christianity or Manichaeism are, where female sexuality is a fundamental source of corruption of evil. That said, with its focus on purity rituals, Zoroastrian scriptures show a notorious preoccupation with menstruation. Moreover, Middle Persian sources and Yashts (Avestan hymns to divinities) have a tendency to feminize the demonic. This may be rooted in that the word druj, "deceit", very roughly the Zoroastrian equivalent of "sin", is a feminine noun (the opposite of druj, asha, is neuter). Several Yashts present female daeva (in this context, demons personifying sinful behaviour) being defeated by male yazata - for example, Mithra, the yazata of the covenant, wields his vazra, or club, in battle against Bushiyasta, the female daeva of sloth.

But while there is a tendency to portray women as particularly suscpetible to evil, this opposition is less "gendered" than one might expect. Neither the wicked female daeva nor the three female good Amesha Spenta are obviously portrayed with a negative "feminization" - they are not passive or weak, nor consigned to nurturing roles. The somewhat famous Anahita (literally, "undefiled"), representing the yazata of the waters, does (logically) bring fertility to herds and fields, but she also drives a chariot into battle to bring victory to warriors. In the Achaemenid period, Anahita, who had a well-attested temple cult (a rare example of Zoroastrian idolatry), displaced an earlier male personification of water in many invocations, "Apam napat" (roughly, son of the waters), usually identified with the Vedic deity Varuna, a patriarchal deity of the Oath and maintainer of order - probably, according to Mary Boyce, originally pictured as the member of an "Ahuric Triad", consisting of Mazda, Mithra and Varuna.

The one instance where there is a clear connection between female sexuality and evil is, predictably, in the case of the Daeva Jeh, personifying menstruation (yeah...), occasionally portrayed as the consort of Ahriman (the personification of destruction and the source of all evil). The Daeva Nasu ("death") is also generally portrayed as feminine and is associated with dead matter - not just corpses, but also blood, hair, nails, and so on. It is interesting to note that hair coverings similar to the distinctive Persian Chador are attested as far back as Achaemenid times (the Satrap Sarcophagus has the most famous example). It is plausible that this is related to a desire to not shed hair on the ground, though as far as I know, this is nowhere commanded or explicitly stated.

Away from these more mythological aspects of Zoroastrianism, the pursuit of spiritual perection (ashauvan) has no overt hierarchic or gender distinction. In practice, however, women were as a rule excluded from religious hierarchies, and the Avestan human heroes to be imitated (Yima, Thraetaona, Karasashpa, etc) are male. There is only one named female in the Gathas, the hymns generally attributued to Zoroaster, namely Pouruchista, Zoroaster's youngest daughter. She is held up as an exemplar of active devotion, bringing benefit not only to herself but to her family and tribe. Debated passages in some more obscure Zoroastrian texts suggest that women could hold clerical positions provided they were able to recite the liturgy, but whether this happened in practice is unclear. It is interesting that one of the texts, the Herbedestan, makes it clear that women could attend religious education of some kind (the word used is obscure) provided the husband was equally able in managing the household. However, women face the constant obstacle that they are viewed as ritually impure during menstruation, and in such situations barred from ritual activity (it is interesting to note that semen, once ejaculated, has the same status of "dead matter" as menstrual blood - but for physiological reasons, this is obviously less of a practical obstacle). The Avestan manual, the Vendidad, expends a great deal of ink on the vice of "wasting seed" (including male homosexual intercourse and intercourse during menstruation) and many rituals to avoid this - however, the Vendidad also has an entire chapter (fargard 14) devoted to dozens of increasingly implausible trials the murderer of an otter must undergo.

Figuring out what all of this meant in practice is very difficult. One thing that is clear is that during the Achaemenid period, it was possible for noblewomen to wield considerable political power (the most famous example being Atosa, the mother of Xerxes). It also appears, by the so-called Persepolis fortification tablets, that women could both head work crews and manage estates. It is also noteworthy that at the end of the Sasanian period, at least two royal daughters, Boran and Azarmigdukht, ascended the throne (briefly). There exists a tradition that a queen was an active participant in a good kings rule, and that the harmonious co-rule of king and queen was reflected in harmony of the realm (see e.g. the romance Vis and Ramin, generally taken to date to the late Parthian period, the 1st century AD or so).

However, legal texts collected in the 7th century, in the Madayan-i Hazar Dadestan clearly illustrate that a system of coverture - legal subordinance of a woman to a patriarch (father, brother or husband) - was the norm, and that obeying this order was seen to be the duty of a good wife, to the point that the husband is sometimes burdened with the duty of ensuring the spiritual well-being of his wife. While women had to obtain consent to marry, divorce was possible, and husband and wife agreed to a contract wherein the socio-economic status of a woman was ensured (such as right to manage the household, raise the children, and inherit from her husband). It was possible for a husband to grant his wife what amounted to "power of attorney" and represent the household in court and partake in his business matters. Notably, any physical abuse of women, even slaves, could (at least in theory) result in the master of the household being fined, along with the perpetrator.

But the husband also had authority over the wife's womb essentially as a vessel for the production of children. A man who was impotent could arrange to have another man impregnate his wife, with any resulting children being recognized as his heirs, with all associated rights. She could also be made to provide male members to carry on her bloodline, in place of a deceased brother, father or other family member (essentially, under certain circumstances, a male child could be recognized as the de jure patrilineal descendant of her bloodline). Marriage appears to have been conceived of in highly legalistic terms, as a contract protected by the community for the purpose of birthing and raising children.

So what does this amount to? While conversion in Persia was very gradual and so we cannot really speak of a "before/after" kind of situation, we at least have some basis for comparison to Islamic law. But this simply isn't an area where I am comfortable expressing a definitive judgment. It is clear that in both socio-religious traditions, women were subordinate to a male guardian. However, there do appear to have been spheres in pre-Islamic society where women at least in theory possessed authority and recognition they did not necessarily possess in Islamic society.

Sources and further reading:

Gender by Jenny Rose (2015) in The Wiley-Blackwell Companion to Zoroastrianism

Marriage Contracts in the Pre-Islamic Period - Encyclopedia Iranica (I haven't actually read this article myself, but Rose recommends it in her closing remarks)

www.avesta.org - a more-or-less complete collection of religious primary sources for Zoroastrianism. The Avestan Vendidad and Middle Persian texts are generally fairly accessible; the liturgy (Yasna) is quite obscure in comparison.

Is there any literature on these topics?: the status of women in Zoroastrianism and Sassanid Persia; the status of women in Byzantium and her near-eastern territories; the status of women under Coptic Christianity pre-Islamic conquest. Especially helpful would be how women of all classes were treated, not just the wealthiest.

To clarify, are you looking for reading recommendations or an answer? I know of only one piece dealing directly with this: the chapter "Gender" by Jenny Rose in The Wiley-Blackwell Companion to Zoroastrianism. A few others touch on it too. I imagine you don't have access to that, so I have no problem doing a writeup if that's what you prefer.