HELP!my 15 month old keeps waking up in the middle of the night

IDK why but my 15 month old keeps waking up in the middle of the night she usually goes to bed around 10 or 1030 and wakes up around 8 or 9 am I turn her TV off around 10 and turn on her night light she knows that means bedtime and usually falls right to sleep she takes a nap around 2 or 3 in the afternoon I don't let her nap longer than an hour maybe an hour and a half but she's been waking up at like 2 or 5 am lately I'm starting to hit the insomnia stage in pregnancy so I'm usually just able to fall asleep when she wakes up she sleeps in her own room but she cries when she wakes up but it's like she don't wanna wake up she will be half asleep but crying like a banshee I try to feed her but she won't accept it sometimes she will drink some milk I change her diaper but it seems to take a lot to get her to go back to sleep she's been pretty gassy the past week or so and I can't get her to eat hardly anything but freaking animal crackers IDK what to do there's no change in temp at night no loud noises I'm not sure why it could be other than maybe teething she's been eating her fingers allot lately any help would be nice she has a sister due in 3 months if this don't stop soon it's gonna be a disaster when the other baby is born no mean comments pls tia mamas