Not recommended. Baby will be confuse with breasts, teats and pacifier. I only gave pacifier at 2 mths old because he had a growth spurt at that time and it was really exhausting. Pull the pacifier every time you see your MIL trying to give to your baby so she knows it's not right.
nooooo please stop ur mil. gv baby pacifier min aftr 1mth old or else baby will confuse nipple and pacifier.
Already check the tongue? Takot ada tongue tie can cause latch problem
Limly Bi