Brief synopsis:
This novel spans a few years of a girl's life during the Revolutionary War Era (maybe 15-18, 1776-1779). She goes about her daily life, marries her husband, and at some point falls in love with a woman. I see her as middle class, maybe upper middle class (if that existed?) Her father is in a skilled trade or maybe owns a small business; her husband does the same.
The problem is that all of the resources I've found center on the roles on women in the actual war. This girl will not be involved at all in the war; her father is anti-politics (which is realistic, as I understand it, because some people didn't choose a side?) Obviously, the war is still going on and effecting their lives in some way, but most of it is about daily life and relationships. At some point, her husband may decide to fight in the war and leave her to manage the family business. I haven't decided yet, or even what side her husband would be fighting for.
Location: I'm not sure. A smaller city or town in the North, not rural. Maybe somewhere where loyalties and the war don't affect daily life so much.
Okay, so, questions:
Lesbian Relationships: What was the general opinion of lesbian relationships? Was it criminalized? Or brushed off, since women weren't taken seriously? Did people know about it? What would be the reaction to two women spending a lot of time together and seeming intimate? What if they were caught kissing or making love?
Puberty: Would a middle class teenage girl know about puberty before it happened? Would she learn it from her mother? Would she know about menstruation before it happened to her? Would she know why she was menstruating and what it meant? What would she use for menstruation, since there were no pads or tampons? Was menstruation shameful? Would she hide away during that week, go about her normal activities, or some combination? What would she use for menstrual pain?
Education: Would an average middle class teenage girl be able to read and/or write? What kind of education would she receive, and for how long?
Relationships: In this era, did a woman generally marry a man older than her, or about her same age? At what age did women typically marry? How common was it for husbands to abuse, beat, or rape their wives? If a man never hit his wife, was that considered uncommon?
Sex: How much would my character know about sex before it happened? Where would she learn it from? How common was premarital sex, and was it criminalized? What were the general opinions about sex from a women's point of view?
Relocating: I think my main character falls in love with a newcomer, not a woman she's known all her life. How common was relocating? If this new girl moved in to town, where might she have come from, and why?
If anyone takes the liberty on themselves to try to answer some of these, I would be awed and grateful. :)
Someone more knowledgable than myself is going to have to come in and answer most of these, but I can give you a start.
First of all, you are going to need to read a lot more about the nature of sexual identity through history. There has not been a static split between heterosexuals and homosexuals, or even between cis-gendered and non-cis-gendered peoples throughout history the way we might demarcate the differences between those two identities today. The FAQ has a fair bit on this, including, for example, this post.
I have one book recommendation for you. You DEFINITELY need to read A Midwife's Tale: The Life of Martha Ballard, Based on Her Diary, 1785-1812. The book is by Laurel Thatcher Ulrich, and won her a Pulitzer Prize, and also got her a professorship at Harvard. It's a well-respected piece. Anyway, the book takes a look at the diary of a midwife from the post-revolutionary era, and unpacks it to discuss all sorts of social history. She talks about pretty much the same stuff you're talking about--public health, sex, relationships, all that sorts of stuff. For example, she gives some insight onto your premarital sex question--of all the attended births that Ballard records in her diary (which she was evidently meticulous about, so we can assume that she did record all births), 29% of the births were premarital. That indicates that premarital sex was pretty darn common. Anyway, this book sounds like it touches on most of the aspects you need to learn about, and entirely does away with the irrelevant sections (politics and war) that seem so prevalent in most revolution-focused texts.