My grandmothers opinions on drinking while TTC

My grandma proceeded to tell me that if I ever drink before I get pregnant that my child will be born with birth defects. Like not if I'm pregnant and haven't found out but even years before I have a child it could still cause birth defects. I tried to explain to her that's not how it works but since I'm the black sheep anyways it's like talking to a brick wall. She also tried to give me a guilt trip for planning on drinking when I go to the beach. I feel like when I do finally get pregnant she's going to cause problems because of this and the fact she's trying to tell my SO and I what we should name our children and how we should raise them. This is coming from the woman who genuinely believes she's a witch who can cast spells and gave me wine and kahlua as a child 🙄😡 I've already warned my parents and my SO that she starts that mess while I'm pregnant and I may snap on an old lady.