Too late to sleep train?

My daughter is 7 months. She has been falling for asleep easily since she was about 3.5 mo and for the most part she sleeps through the night. If she wakes up she can get herself back to sleep. For the 1-2x per month when she couldn’t get herself back to sleep, I would give her a bottle to help her and that always worked.

Well fast-forward to the past couple weeks when she is working on learning how to crawl. There have been 3 or 4 nights when she has had a hard time falling back asleep on her own. I’ve given her a bottle in the middle of the night probably 4x over the last week. I never developed another way to get her back to sleep other than giving her a bottle, and I don’t want to make this a consistent habit.

Is it too late to sleep train? Any suggestions?