Waking up an hour after bedtime!

The past week DD had been waking up about an hour after falling asleep screaming and the only thing that comforts her is sucking on a bottle. She eats 6 oz before bed and when she wakes she will only eat a half an ounce to an ounce so I know it isn't really because of hunger. I know the past few days have been a little hectic with my FIL passing away yesterday but this started last week. She will be 24 weeks on Sunday. Any ideas why?? I don't want her to start relying on a bottle to sleep!