Should I buy another baby play mat?

My baby loves her play mat. She smiles, screams, laughs, kicks, etc. when she’s laying on it. But it’s a small mat so she often falls off from kicking so much. Obviously on the floor, lol, but she hits her legs on the plastic siding. Do you think it’s worth buying another mat since she loves them? Or no because they outgrow them fast? She’s almost 4 months old!