Sleep regression

My daughter is 12 weeks old. We started a bedtime routine around 2 weeks ago and she’s stuck to it slept from 8pm till 6am straight through no waking up. Around 3 nights ago she’s started waking around 2am and not going back to sleep until 4/4:30am and then waking at 7/7:30am. I was wondering if I should let her sleep till then because she’s missed out on sleep or wake her at her usual time of 6am to keep her routine and bottle/nap times in the day the same? She’s goes to bed on an 8oz bottle and has and 8oz in the morning (7oz in the day) but when she wakes at night I give her 4oz and she’s back asleep by 4:30am so should I wake her at 6am to keep things the same as she’s could just be going through a regression/growth spurt. Because waking up at 7:30am messes with her bottle times and I have to try work them so there is enough time between them and so it works where her last one is at bedtime. Any advice greatly appreciated as I ask my fiancé, mum etc and they just say they dont know or let her make her own routine but I want her to have a structured day/night so it makes life easier for us. I know there is going to be times when things change and don’t go to plan always but I would like to keep things the same/similar as possible. Thanks in advance