Helper on phone

I warn my helper 2x.. and told her to put the phone on the dining table , only uses it only during her break time. But I know my 2month old LO, needs to be carried constantly, once u put him down in this bassinet, he cries. So I allow the helper to use the phone to watch movie when my baby is sleeping on her (soundly then to put baby back in his bassinet). Den recently she kept using n using taking it for granted. EG, I’m taking care of baby in the room, and she is using her phone at the living room. I dun wanna b too stern to her, as eventually after ML I’ll b back in workforce, I dun wan her to ill treat my baby. What Shld I do?