We were ready at 18m with #1, and she transitioned to an essentially side-car daybed (converted crib) at 2. It took her 6 months to be ready. At 4, 100% of her sleep is in her bed although my husband will visit her sometimes. My son is 17 months and I'd love to send him on his way in a month or so although his expressive language is severely limited right now and he may need more time.
No judgment op. My opinion is that some limited, gentle separation (independence) is good. But who is to say what the timeline should be. It may vary by adult/child.
Danielle, Nick, Gigi ('08) and William ('11)