6 months old baby

I’m 1st time mom and my baby is 6 months old going 7 in the next 2 weeks. She doesn’t like to roll over, tummy time and can’t sit on her own pa. 8.8kls na si bby and according sa app, dapat daw 7.3 to 7.9 lang yung timbang niya. But would like to those experienced mom na normal lang ba na ganito si bby? #advicepls #worryingmom