How Do I Handle My Mother-in-Law's Superstitions During Pregnancy?

I love my mother in law. I love my mother in law. I love my mother in law.

She was born in Mexico and doesn't speak English and thinks she knows what a pregnant lady and a baby needs, but a lot of it is based of old Mexican superstitions. Like I have to wear red when I go outside or else the moon can hurt the baby. Have to tie a thing of fabric around babys belly so his belly button doesn't pop out. The latest one? You're not supposed to wash baby clothes and blankets before baby wears them because the soap is too rough.

Also. My feet are starting to swell and I told my husband last night that I needed to cut back on my salt intake and he should tell his mom that too cause she's staying with us and has been cooking. What does she make this morning? The saltiest dish she knows how to make. And also one of my favorites. I love my mother in law. I love my husband. Dear Lord help me not yell at either of them.