MIL smelling baby consistently and causing strained r/s with hubby

My MIL is the caregiver for my first born and I keep noticing her smelling my baby every few seconds. Mind you, every few seconds. I previously told her not to kiss my baby but even though she didn't kiss her mouth is still touching my baby side of the head when she smell. I feel its quite disgusting to have someone to keep smelling you every few seconds and tried to tell my hubby about it. However he told me that he is having a strained relationship with his mother as he had told her not to do a few things, like to feed her only when she is hungry or every 3hours and not everytime when she cry to prevent overfeeding. So he say this is a minor issue if I can't tahan I should tell her myself. In a way I understand but I can't help feeling alone and without support. Any advice on how I should tackle this issue?