A., i will address the "what to do" thing but i wanted to first warn you, my son started acting real interested somewhere around 18 months, and some people told me, "oh yeah, he's ready!" he was very articulate and has a great vocabulary and acted like he knew exactly what he was supposed to do. then i mentioned it to my daycare provider (who i trust implicitly!) and she kinda said, "well...he'd be the youngest little boy i ever had!" and i could tell she was pretty skeptical. when i asked her she said, 99% of the time, they act really interested around this age, then the "new" wears off and they lose interest. sure enough, he got to the point where he'd fuss if i even mentioned sitting on the potty. sooo we let it go for awhile, and he's now 26 months and just starting to get back into it. SO my point is, support her, encourage her, but don't force her, because it could be that she is just interested because it's something new. if you stick with it she might skip over the not being interested part. who knows! just be prepared, is all i'm saying. i couldn't help but be disappointed when my son started refusing to sit on it. but he never got as far as your daughter is, either.
ok so the other thing i wanted to say is, regardless of how good she's doing, also keep in mind that with your trip coming up, it is possible that she will regress. just take her cues and go by how she seems to be doing. we moved recently and my son was back to square one. it may not matter how you go about it, the disruption of her schedule and not being home might just be too much for her to focus on pottying. i'm sorry to sound so negative, i don't mean to be - and keep in mind i have a boy and everyone says they're harder. you may have none of these issues - i hope you don't! Lol...
SO as far as your actual "question", i would just play it by ear. i honestly don't know what the "best" answer would be, i'm sure it's different for everyone. public restrooms worry me too, but it's kind of a fact of life. good luck and i hope she keeps going in the right direction! :)