Child's development

Alexis • 3 year old Chloe💖 11/15/15 & Jacob 💙 3-5-19
So my daughter is 7 1/2 moths and I feel like she isn't doing anything I think she should be. She isn't sitting up on her own, holding her own bottle, and she doesn't have any teeth yet( not quite the same). I thought around 8 or 9 months a lot of babies started to crawl, which she'll be in 2 weeks. As far as holding her own bottle she is breastfed and I stay at home except 2 days a week I work overnight so she'll maybe she 2 bottles. I try during the day to give her a bottle and she gets the concept of putting her hands up but I guess her strength isn't there because if I let the bottle go it'll fall. Does anyone have any things I can do to encourage her to hold her own bottle and sit up on her own? Or should I wait another month or so to see what happens? 
P.S she can scoot if she really wants something like my phone or the remote. Lol