Just a thought - are you sure she's not actually using this sucking to put herself off to sleep and then just waking after one sleep cycle (which is usually anything from 20-45mins and a very normal pattern for a small baby)?? If this is the way she is soothing herself off to sleep, I wouldn't interfere with it, I think it's a very valuable skill and much better than a dummy.

If, however, you are rocking, patting her to sleep etc and then her hands are waking her up, well that's another story.

I'd be very surprised if a 2 month old was teething, although it does happen. Sucking on their hands is just a developmental phase, she's just learnt a new trick, that's all

The above suggestion of tight wrapping is good, that's what I'd try. Luckily it's cooler weather, but just be careful not to overheat her either.