Baby sleeping on side safe?

Ca

Our little girl will be 4 months on the 19th. She hasn’t rolled over yet but can roll to her sides. She’s been rolling onto her side to sleep in her bassinet. Should I let her sleep that way? Is it safe considering she can’t roll over yet? What if she accidentally rolls onto her tummy and can’t get back onto her side or back? Ahhh so many questions!I feel like a paranoid FTM 😜😳