I feel like my baby is behind on her milestones.

She's 6 months and a week, and all she can do is sit unassisted which she's been doing for a month now. She can stand with help, but can't pull to stand. She can't roll over from belly to back, she can't crawl. What should I do? I know I shouldn't compare her to other babies lol I just feel like she should be able to do more than sit?