Baby’s sleep help

My lil one is 3 weeks old and she wakes up at 1-1:30 am for a feed. The issue is she seems to think it’s time to get up at this time and won’t go back to sleep. Then she will have an hour sleep at 4 am and wake up for another feed at 5:30 how can I get her to go back to sleep after her 1:30 feed.