How to get 1yo toddler to sleep longer

My 1 yo girl still doesn’t sleep through the night and wakes up every 2-3 hours.. it’s manageable in the day with my mil help but we have been particularly sleep deprived esp the weekdays whereby we have to trudge to work. Any thoughts on how to improve the situation? She usu sleeps 1.5 hr in morning, 1.5 hr in afternoon, then goes to bed around 9 pm with the 2-3 hr waking .. we tried lullabies, giving her 210 ml milk b4 bed (instead of usual 150), letting her sleep less in day but to no avail.