Baby carriers

I know lots of people baby carry. I have carried my stepson (after he was 2 years old) and am planning on carrying my new baby. My MIL told my husband she thought this was a terrible idea and that babies fall out of them all the time. I really think this is just another thing for her to criticize me for (she got mad about us buying grass fed beef to freeze... she eats beef herself but somehow thinks beef from the grocery store is more humane than buying from the farm) so anywho.... I've only used ergo and tula carriers and I really don't see how your baby or young child can fall out if they arr used correctly. I have even practiced with a baby doll and a moby.... I know there is some risk with anything you do, even holding baby in your arms, but really? Please assure me baby carrying is fine.