Early crib to bed transition?

How early is too early to transition to a bed? My baby refuses to sleep in a crib. She rolls over, feels the rails next to her and flips out. She will, however, sleep blissfully in my king size bed. Anyone transition to a bed really early? Both of my older daughters were in a queen size bed before 2 (with guard rails). However, my baby is only 9 months, so I can’t do it yet but I’m wondering when???