hates tummy time, doesn't push down with her legs and can't roll

Hi everyone! My daughter Sophia is 4 months and 10 days old. When she does tummy time, she goes into airplane mode (legs in the air, arms out to the sides slightly behind her). She doesn't bring her arms to the front and she lifts her head only for a couple of minutes and then starts to cry. She will keep crying until I pick her up. Also, she doesn't push down with her legs when I hold her in a standing position. Even though our pediatrician says its ok and that she needs time, I'm really worried.In addition, she hasn't started rolling yet. I think my daughter has weak arms and legs.I signed up for a series of massage therapy to strengthen her muscles. Is there anyone else who has the same problems? Any input will help! Thank you in advance!