MIL. Always, ALWAYS my MIL.
Some background. First person in the family to breastfeed, gentle parent etc. First of friends to have a baby, my own parents several hundred miles away so I was a bit isolated.
Hated DS1 & DS2 names because we refused to go with the "family tradition" of permitting the paternal grandmother to pick the name (her taste is awful).
DS1 was 9 days old. Requires both boobs every 3 hours takes him an hour to finish a feed, cluster feeds from 7-10pm. DH and I exhausted. Day 9 he fed ALL night and then cried most of the day. MIL suggests we buy a swing chair thing. We refuse because we don't have room in our tiny living room. Next morning, 8am, we've finally all fallen asleep having had about 45 minutes sleep the night before, MIL arrives with FIL and the enormous swing we told her not to buy and instructs FIL to set it up so we cannot return it. Then she places DS1 in chair and when it made him scream more, told me my milk was clearly not enough for him and he was so clever he knew he wasn't getting enough nutrients from me so I should just give up the breastfeeding.
That night, I was flicking through the jokey Haynes baby manual a friend had bought us, only to find out about growth spurts.
With DS2, I got less mean stuff, or perhaps I paid less attention. The day after he was born a registrar sang the theme tune of a children's TV programme as he discharged me because DS2's (moderately) unusual first name is one of the characters. Had I not just had an unexpected breech birth, I probably would have clocked him one.