Ouch, poor thing having all those teeth to cope with
I agree the teething is bound to be causing some of those NWs.
You may well find that with gradually pushing the first nap out, it starts to lengthen by itself and she ends up dropping the second nap herself sooner than you might guess. If she can pull nice long nights when she needs to, that's great
But I think that by pushing gradually rather than going to one nap cold turkey, there's more chance of it lengthening naturally and then she'll cope with it better... I say this with the caveat that mine have both kept their naps for longer than most so I don't really have btdt experience with early nap droppers or with pushing the first nap out like this, but there are plenty of others around who do, once you get to that point
I wouldn't be waking her from the first nap, just push to 11 (preferably not letting her sleep in beyond 8am), hold for a few days and see what happens, then push to 11:15, etc etc. Definitely let her sleep as long as she wants for this nap. The second nap will gradually shorten and you may at some point find that she starts refusing it, then you'll do EBT and at this stage you probably will end up with some 1 nap and some 2 nap days and that's completely normal
As for how long to let her sleep for the second nap...sorry it's hard to say, it would depend on how her first nap went, I would think. Just consider how much sleep she's already had and how much A time to BT you think she'll need to settle easily without being OT, bearing in mind her total sleep needs over 24h (do you have a feel for this?), does that make sense at all?