I could SCREAM!!!!

I let my mother watch my 6 week old daughter for 2 hours yesterday evening and when I returned she told me that she had given my daughter 2 oz of water!!!!!!!!!!!!! I specifically told

her that babies should NOT receive water under 6months and she doesn't fucking listen!!!!!

This is 3 weeks after she bought my daughter formula and told me that she was surprised I was still breastfeeding and that I needed to switch over to formula?????????????????????

What do I do?

I don't want to start problems but I don't understand why she went out of her way to ignore my wishes