My MIL read my 2 yo a sex education book

We found it at her house today and I was like wtf is this and she was like “we skipped over the part when they had sex” like uh every single page is a naked mommy and daddy. And one page shows a baby being pulled out of a vagina with the Mom laying on a hospital bed. So then I was like why would you read that? And she was like “I never read it” and my husband was like “you just said you did and that you skipped over certain parts” ......... I’m sorry what. I’m FUMING. My baby is 2!!!!!!!!!! Why does she think it’s ok to take it upon herself to teach my child about something like this.