8mo baby sleeps very little

My baby sleeps about 9-12 hours in total on average per day. She’s 8.5 months old, has 2 bottom teeth and just learnt to sleep through the night (6-8 hours) in her 7th month. Her bedtime is usually around 11pm-1am, and we are trying to push it earlier to around 9 or 10pm. Feel bad cause I know babies are supposed to sleep around 7-8pm. Our lifestyles are to blame as I usually work till 8 or 9pm and we hired a helper to take care of baby. It’s around night time that we all reach home and baby gets excited to see us and the house gets noisier at night as compared to daytime when it’s just her and the helper. On “good” days she sleeps from 11pm to 7am, but as we’re pushing for earlier bedtime now, she recently sleeps around 930pm, wakes around 4am, we soothe her back to sleep without feeding till 5am, and then she wakes up around 830am. But we still haven’t established a fixed schedule, sometimes we try to make her sleep from 930pm but she resists and doesn’t want to sleep till 1230am. She stays awake for 3-4 hours between naps and sometimes up to 5 hours before bedtime. We feed her milk 4 times per day, 210ml per feed, 3.5 to 4 hours apart. And give solids like cereal, fish porridge, etc around 1pm and 7pm. Googled that babies her age should sleep at least 12 hours per day and it’s worrying me cause she hasn’t hit the bare minimum for weeks.. recently she sleeps just 9-11 hours each day. But hubby thinks it’s fine cause she’s been progressing pretty fast compared to my niece; my baby can babble, pincer hold, clap hands, roll, sit up, cruise and stand without support for a few seconds. Not sure if that’s the basic for her age though. She weighs around 7.5kg. Should I bring her to PD, or just keep trying to fix a schedule? Thanks in advance 🙏 #firstbaby #firstmom #pleasehelp