Having had only one lesbian date, which wasn't successful, I can't really give you solid signs or indications. But I should hasten to add I wasn't that interested in her anyway, especially not after she expressed her admiration for one of the most lunatic extreme right wing fringe wannabe politicians in Australia. She wasn't a good match for me so it didn't bother me it didn't work out. But we still talked for over three hours.
Likewise I've been on plenty of dates with women in dude mode where we talked for hours but which ultimately went nowhere. Even if it was multiple dates. All were romantic fizzers for them and me. But then I was never into being romantic, it always felt so confected. There was only one woman I ever went out with that I actually felt a strong connection to and she for me...and I have to say I didn't find her very physically attractive at all but there was something about her that really turned me on. I feel it boils down to chemistry - and I don't mean to be trite or cliche by saying that. Either there's a two way connection or not.
The only "successful lesbian dates" I've seen have been in TV shows like Orphan Black but those involve young and feminine women and are no doubt fanciful fictions. Sense8 depicted a lesbian relationship with one of the partners being trans, but the dating process wasn't really touched on and the characters were young (30s?) and attractive. Realistic? Dunno. I have some lesbian friends in relationships, I guess I should get some advice from them.
But yeah, chemistry - what is that elusive thing? And is it different for women who like women?
I guess my advice, for what it is worth coming from an unsuccessful one timer, is to relax, enjoy your time together. That way you can see if she is contributing enthusiastically to the conversation and check her interaction/body language towards you. It took me a long time to realise that just because a woman is talking to me (even for hours) it doesn't mean she's interested in having a relationship with me. Women are usually complex and each totally different from the other, trying to work out what they mean by what they say and do is a slippery slope to going insane... so just go with the flow. Even if someone seems interested they might not be. I knew a woman who was in a hetro relationship, she was attractive and vibrant and a total flirt, it drove most men nuts but I just knew it was her way of interacting with people so I kept myself aloof from all that.
Anyway, I'm rambling, sorry.
I'd say try and mix it up - if you get a second date maybe make it less of a sit down and chatting date and more of a going somewhere and walking around doing something date, try to allow it to be a bit random, relaxed and fun. If you have the tendency to talk about the troubles of the world (one of my pitfalls), don't. If you have a tendency to be a bit negative/cynical (again, one of my tendencies) then keep it fun and positive.
Yeah, I dunno - sounds like I'm writing advice for myself, not for you. Lol!
Good luck, Suzi, you will meet someone who you click with and who clicks with you. It may take one date or it may take several but when the chemistry happens you'll feel it.