R.D.
My son did this a few months ago. He was very sick and not sleeping through the night because of that and then it just became routine. Did something happen recently to make her not be able to sleep at night? Maybe she needs a change in her routine? Have you tried putting her to bed even 15 minutes later and that might make a big difference. Rest assured, my son went back to sleeping through the night and now goes to bed at 8 and sleeps until after 7 most mornings...and he turned 2 earlier this month. She will get back on schedule :). Good luck and congratulations on the new little one coming!