5 months, baby, not able to flip over, and didn't go out much. Is this normal?

Hello, I'm a working mum. Hence, my baby is left alone with my helper. I am not comfortable letting her bring my 5 months old out because of safety issues. So my baby is always at home. Also, I noticed she's not able to flip over yet, which worries me as I thought by 4 months she should be able. Does anyone encounter this, too? #pleasehelp #advicepls #firstbaby #firsttimemom