Dealing with MIL

Brooke
My MIL will be watching my son once a week while my husband and I work and I'm dreading it. I want to stay home but my husband doesn't understand why when his mom can watch him. (Since I've had my son everything she does annoys the shit out of me)  I'm exclusively breastfeeding and everything is going great but when he gets hiccups she tells me I need to give him water (which is bullshit) and if he spits up she says I need to give him solids (she wanted me to start solids at 1 month?!) I've told her and my husband has told her absolutely not!  The doctors don't recommend it and things have changed since you've had a baby. I'm afraid when I leave for work she will do everything I asked her not to do. Anyone else experiencing this? What can I do to scare her? Lol she's not my only option for baby sitting but my husband doesn't want to hurt her precious feelings. She's starting to hurting my marriage...