Women of the higher classes mostly had to obey their guardian and where often used as a resource for securing good relationships with other families or to get on someones throne, etc.
But how was that for women of the lower classes, especially farmers? Sure, their families werent surely less patriarchal, but how much could they say who they wanted to marry?
Oh look, it's an opportunity to geek out about the Pastons!
One problem we have when it comes to the viewpoints of the medieval lower classes, in particular women, is that we have very few of their voices. But we do have the Pastons. The Pastons were an English family who, over the course of the fifteenth and sixteenth centuries, gradually worked their way up from one-plough farmers to established figures at the Tudor courts. And they are possibly my favourite family in history because they not only wrote each other letters, they kept them. For centuries. Starting in the early 1400s.
When it comes to your question, another problem we have is that when there's no recorded opposition to a marriage, it's hard to know whether the bride and groom chose each other themselves, whether their families made the decision and they went with it willingly, or whether they resisted the marriage but gave in to family pressure. Alliances for the benefit of the family were a thing among the lower classes as well as the nobility.
But one way to examine how much say women had in who they married is to examine what happened when they tried to exercise that say - in other words, when they opposed their families' marriage plans for them.
One example is Elizabeth Paston. She was born around 1429, into a generation of Pastons who were in the early stages of pulling themselves up from poor farmers to educated members of the squirearchy. When she was twenty, her brother John was good friends with a very wealthy guy called Sir John Fastolf, and the family wanted Elizabeth to marry Fastolf's stepson, Stephen Scrope. He was fifty and ugly, and Elizabeth refused to marry him. Her mother Agnes did not take well to this: she kept Elizabeth isolated, and beat her regularly. Here's Elizabeth's cousin writing to Elizabeth's brother John, in 1449:
...sche was never in so gret sorow as sche is now a dayes, for sche may not speke with no man, ho so ever come [...] And sche hath sen Esterne the most part be betyn onys in the weke or twyes, and som tyme twyes on o day, and hir hed broken in to or thre places. Wherfor, cosyn, sche hath sent to me by Frere Newton in gret counsell, and preyeth me that I wold send to zow a letter of hir hevynes, and prey yow to be hir good brothyr, as hir trost is in zow...
(She was never in such great sorrow as she is nowadays, for she may not speak with any man, no matter who comes... And since Easter she has mostly been beaten once or twice a week, sometimes twice in one day, and her head injured in two or three places. Wherefore, cousin, she has sent to me by Friar Newton in great secrecy, begging me to write to you about her suffering, and to pray you to be her good brother, as her trust is in you...)
Elizabeth won her battle. She didn't marry Scrope, and a couple of other marriages the family tried to arrange for her also fell through. Almost ten years later, she married Robert Poynings. (Her relationship with her mother seems to have remained, unsurprisingly, strained: the language in her letters to Agnes is elaborately polite but formal, with a tinge of what comes across as bitterness.) So Elizabeth did have the final say in who she married - but it wasn't like she could just make her choice and that was the end of that. Her family clearly felt that they should be making this decision, she should be marrying for the benefit of the family rather than to suit her personal whims, and it took a serious fight for Elizabeth to get her way.
Another, opposite example is Margery Paston, who a generation later wanted to marry someone against her family's wishes. Margery was born in 1448, and sometime around 1469 she announced that she wanted to marry - or had already secretly married - the family's bailiff, Richard Calle. The Pastons were well on their way up the social ladder by now, with the help of a large but hotly contested legacy that Sir John Fastolf had left to John Paston, and they were Not Happy about this. Calle wasn't an advantageous marriage, either socially or financially. John Paston wrote to his brother Sir John Paston (yes, this family named two of their sons John, just to wreck our heads):
and my fadyr, whom God asoyle, wer a lyve, and had consentyd ther to, and my modyr, and ye bothe, he shold never have my good wyll for to make my sustyr to selle kandyll and mustard in Framlyngham
(Even if my father, whom may God save, were alive, and had consented to this, and my mother, and you both, he [Calle] would never have my approval to make my sister sell candles and mustard in Framlyngham.)
The Pastons kept Margery and Richard apart for a while. Sometime in 1469, Richard wrote to Margery emphasising
the gret bonde of matrymonye that is made be twix us, and also the greete love that hath be, and as I truste yet is be twix us, and as on my parte never gretter; wherfor I beseche Almyghty Godde comfort us as sone as it plesyth Hym, for we that ought of very ryght to be moost to gether ar moost asondre; me semyth it is a mll. yere a goo son that I speke with you. I had lever thenne all the goode in the worlde I myght be with you.
(...the great bond of matrimony that is made between us, and also the great love that has been, and I trust still is between us, and as on my part never greater; wherefore I beseech Almighty God to comfort us as soon as it pleases him, for we who ought by right to be most together are most apart; it feels like a thousand years since I spoke with you. I had rather than all the good in the world that I might be with you.)
In this letter, he's clearly a little worried that the family is getting to Margery, and is urging her to stick by him. She did. The family actually tried to get the marriage voided: they hauled Margery and Richard in front of a bishop, so he could lecture Margery on what a terrible idea this was, question the two of them, and find out whether whatever they had said to each other actually constituted marriage. Margery was not intimidated by this and had no intention of backing down. Her mother writes to Sir John:
And the Bysschop seyd to her ryth pleynly, and put her in rememberawns how she was born, wat kyn and frendds that sche had, and xuld have mo yf sche wer rulyd and gydyd aftyr hem; and yf she ded not, wat rebuke, and schame, and los yt xuld be to her, yf sche wer not gydyd be them [...] and seyd that he woold undyrstand the woords that sche had seyd to hym, wheyther that mad matrimony or not. And sche rehersyd wat sche had seyd, and seyd, yf thoo wordds mad yt not suher, she seyd boldly that sche wold make that suerher or than sche went thens, for sche seyd sche thowgthe in her conschens sche was bownd, wat so ever the wordds wern.
(And the Bishop said to her right plainly, and reminded her how she was born, what family and friends she had, and still should have if she would be ruled and guided by them; and if she did not, what rebuke, and shame, and loss it would be to her if she were not guided by them...and said that he wanted to hear the words that she had said to him [Calle], whether they made matrimony or not. And she repeated what she had said, and said, if the words didn't make it sure, she said boldly that she would make it sure before she went thence, for she said she thought in her conscience she was bound, whatever the words were.)
After this, the Pastons gave up and let the marriage go ahead, but they cut Margery out of the family, at least temporarily: her mother Margaret wrote that 'I charged my servants that she should not be received in my house'. Again, Margery did get the final say, but her family clearly didn't think she should.
These are only two examples, and it's hard to know how far we can extrapolate from them. Agnes, for example, was clearly a formidable woman, and she doesn't come across as a particularly nice one; just because she tried to beat her daughter into marriage, that doesn't necessarily mean it was standard practice - in fact, the cousin's letter implies that Agnes is taking things too far. And the Paston family in general was clearly unusual, very determined, and very focused on social status - their social rise was highly unusual, and the letters show a family full of intelligent, efficient, forceful people who made plans and didn't easily give up on them. So it's hard to know whether it was standard for women of their social class either to face that level of pressure when it came to marriage, or to put up that level of resistance. But in these two cases, at least, the women were definitely expected to marry for the benefit of the family. The women got the final say, but only after massive struggles.