My 11 month still don’t know how to crawl

My baby was born with neck tightness so it may caused delay along the way. But now her neck and head is way better but she still doesn’t crawl or pull to stand. Keep going therapy and treatment but the doc say is not necessary to crawl but if don’t pull to stand by 11-12 month it shows developmental delay. I don’t know what to do. Each baby have their own milestone isn’t it?