Now there’s a can of worms.

The short answer is ‘yes, after Gardner started it and decided to call it a coven’.

The longer answer is that there were various groups in the area doing vaguely esoteric things, including a theatre group that had an inner circle that claimed to be Rosicrucians, and groups that were a bit like the Boy Scouts, but who did rituals in the nude that were what they thought Native American religious rituals would be like.

In this environment, and inspired by Margaret Murray’s (now discredited) idea that there was an ancient religion that was persecuted and almost wiped out, but survived in small pockets across Western Europe, Gardner was able to gather people that were interested in naturalism and the idea of magic.

With some help from Aleister Crowley, and then a lot of help from Doreen Valiente, this turned into what we now know as Gardnerian Wicca.

So, no, Gardner didn’t ‘find’ a pre-existing coven, but he did find groups that he decided, either naively or creatively, were remnants of what Murray described.

He probably did find people doing rituals, yes, but they were a mixture of Masonic ritual, spiritualism, initiations from trade guilds and friendly societies, classicism, and nonsense ‘Indian’ stuff inspired by Western novels.

Gardner took all that and added some kinky sex stuff, and made a ‘coven’. Early Wicca was very different to what it is now, and would probably upset and shock a lot of modern Wiccans.

Doreen Valiente is pretty much single handedly responsible for turning it into what it’s like now, and making it into a goddess-centred pagan religion, instead of a club for kinksters that liked knives and wife-swapping and long-winded ritual magic.

TLDR; ehhh... nah... kinda... sorta.... maybe but not really...