Apart from anything else, for as long as she is upset about your interference in her relationships with her friends, her ability to concentrate on her schoolwork is likely to be at least somewhat impaired.One of the other people who responded to your question raised the issue of the age of consent.One thing you haven't discussed very much in your account is your daughter's relationship with her other friend (the one who is aged 13 or 14).I'm not sure what your attitude is towards friendship, but unless some obvious red flags are apparent there, I'd be inclined to avoid doing anything that might give your daughter (who is currently very sensitive about the interference of her parents in her relationships with her peers) any additional cause for resentment.(There are a couple of points I would have liked a little clarification on: for instance, the wording of your description about how your husband was informed about your daughter's lesbian crush made me wonder if you are actually divorced and living in separate households, which would presumably make it more difficult to coordinate the way you handle some of the issues that are liable to arise in connection with your daughter’s upbringing.) Regardless, it does seem clear that there was a considerable failure (or several failures) of communication along the way.
You do sound like a deeply caring parent, but it may be the case that you and your husband would benefit from at least a degree of professional help to come to terms with the possibility that your daughter will turn out to be gay, as well as getting some guidance regarding the best way to deal with some of the issues connected with that possibility.
If you disagree with an answer, it is okay to post a short comment explaining why you are (presumably) downvoting it, but let's keep it civil, and directly to the point.
As a heterosexual male who has never been in a situation anywhere like this, this is EXCELLENT advice.
As a PIA growing up, my parents tended to let me sort through my own problems, and it helped me to mature as an individual, especially knowing that I could make mistakes on my own, without them interfering.
Now this is just my perspective as a recent teenager, but I joined the community to upvote this post. 1I would recommend instituting something of an open-door policy (to the extent of your choice) so as not to disrupt an otherwise healthy and platonic relationship.