How can I get longer night sleep? (opens in new tab)

Am I doing something wrong I feel like my almost 10 month old sleeps so little at night and her wake windows are so long. I used to be able to nurse her back to sleep when she wakes up before 6 but she doesn’t seem to go back down anymore. Not sure if it’s a schedule thing or maybe she’s still hungry because I’ve started to introduce more formula throughout the day as my feel my supply is dwindling.