10mo DS now spends Mondays at MIL house for childcare while me & DH both work on Mondays.
Drop off around 8am and pick up around 5pm.
She was very keen to follow our 'routine' and asked us to write it down for her so she could stick to it. He has 3-4 7oz bottles a day usually 7am, 11am, 2pm and 6pm. He usually drinks all his milk, as well as his 3 meals.
The first time MIL looked after him she tried to give him a bottle at 11am but said he didn't want it, only drank 2oz then refused the rest. I totally accepted this because it's all new to him, he was probably distracted and confused in a partially new environment. I held hope that because he refused this, he would easily take his afternoon bottle at 2pm.
When we picked DS up at 4:30pm I could tell he was cranky and tired but he had had a big day so that's what I put it down to. He had done really well.
She called later on in the evening after DS had went to sleep to have a general chat, (we all get on great and DH and her have a lovely relationship) we asked her why only 1 bottle had been used (we packed 3 just in case) and that's when she told us she didn't make him another bottle because she didn't want to waste more milk and he ate all his pasta for lunch anyway.
All day he only had a total of 9oz when it should've been 21oz by this point!
DH tried to express how important it was to feed him the afternoon bottle as he was really hungry, wasting milk isn't an issue at all and we would rather waste milk than DS go hungry.
Fast forward to yesterday, the is second time she looked after him and the same thing happened. She didn't give him his afternoon bottle, she said 'well he ate all of his pasta for lunch so I didn't bother'.
DH had made a point about giving him this bottle when he dropped him off in the AM, also by text just to remind her that he will probably be due his afternoon bottle soon etc.
When he got home we made him a bottle straight away. I've never seen DS so hungry, he was ravenous. He gulped down a 9oz bottle (usually drinks 7oz before bed) so fast it was gone in about 60 seconds. I felt so bad for him. He was so hungry, I know he's not ready to drop this afternoon bottle yet. His routine is working fine.
AIBU to be quite annoyed with MIL about this?
YABU - I wouldn't be annoyed
YANBU - I would be annoyed too