Show your support
It's not bad for them, it's just not good enough as a main drink. You haven't said that they have an intolerance (eg. You have had to cut it from your diet whilst breastfeeding), so they should be fine. Cows' milk can be used in cooking or mixed with food from around 6 months but should not be given as a main drink to babies until they're 12 months old. This is because cows' milk does not contain the right balance of nutrients to meet your baby's needs. https://www.nhs.uk/conditions/baby/weaning-and-feeding/drinks-and-cups-for-babies-and-young-children/
Try not to worry! But definitely get your partner to have a stern word with his mother!
Don't worry at all , unless baby has an intolerance it shouldn't have any effect. It's just not as nutritional as breast milk or formula which is why it's not advised as a main drink. But they say in food or cereal etc from 6m is fine x
No need to worry. You shouldn’t be replacing breastmilk or formula before 12 months but it’s perfectly fine for them to have it. My 9 month olds have it on their weetabix every morning 😊 Ask her to use whole milk though, not semi skimmed, and not in place of his usual milk feed.