DD is 7.5 months and still can't do it herself.

We only give her a pacifier at nap/bedtimes. If she wakes up, all we need to do is pop the pacifier back in and she goes right back down. I would love it if she could do that herself instead of having to do it 3-4x per night. I thought I'm not sure if she's just not getting enough exposure to it during the day to figure it out on her own, or if it will just click for her around a certain age?

How old was your LO when they figured it out? Did you help him/her with it?