5 month old having trouble sleeping

Of course in the beginning she wasn’t sleeping well.. but around 2 months she would sleep well through the night. In bed at 8:30 and asleep until 7.. now at 5 months she won’t go to sleep until 9/10 maybe later and then is up every couple of hours to every hour!! I usually bring her into my bed and she loves that and will sleep hours in my bed with me.. but when dad is home we just can’t do that!! He is a very heavy sleeper and he could easily crush her so if I do end up bringing her in, I’m not sleeping! I use white noise, she gets a bath and a bottle before bed... I’m just not sure what to do at this point.. any advice?