S.M.
This won't help much, but it sounds like you might just have early risers. Have you tried leaving some toys with the 5:30 waker so she can entertain herself in the morning? I have found kids have very strong internal clocks, and she may just be prone to getting up then - which means it is wake-up time for mom too :) IF you want them to stay in their cribs longer, maybe just go in, open the blinds, give them some toys and try to go back to sleep for another 30 minutes. But I don't think there is much to do to keep them sleeping longer.