16 month old, only stands on the couch.

[PeraltaSpidey]

Hi. I have a 16 month old girl who was 6 weeks preemie, with growth problems in the womb, too. So was only born 3lb6. She's still absolutely tiny, and is in the lowest 9/10th percentile for weight- and borders on what's normal for an 11month old. So shes about 5 months behind physically. Which is fine, and isn't a worry for me or the Health Visitor. She's also pretty advanced socially and with her speech.

The one thing I'm worried about with her beginning to walk.. She shows virtually no interest in it yet- she's very good at crawling, so I think she is taking that option. She can pull herself up on the couch/furniture with some effort, but doesn't surf etc and she can do steps if I hold her hands. Except she is very very good at standing up on the couch/ bed independently, which I'd argue is harder than standing on the floor, but she can't stand on the floor.

My question is, how do I help transfer her standing up on the couch skill to the floor? I just know if she tried it, she'd find it fairly easy. Thanks for any guidance.