9 MO waking up and won't go back to sleep for 1.5 hrs

[Mel-Lisa]

Hello,

My little one (9 months) is finally waking up less again (sometimes around 8 or 10pm) but then she wakes up at 3.30 and just won't go back to sleep until around 5 or she falls asleep in the cot but a few minutes after I leave the room, she rolls onto belly, starts crawling and stands up. She's been doing the crawling and standing for a couple of months now, so it's not really new for her.
I do everything the same way that I would usually do at night wakes - going in, lying her back down onto her side and making sure she won't roll onto belly, touching her as little as possible. DD seems rather tired but so active. I've tried feeding her, but she wasn't very interested. If she is awake when I'm leaving the room, she starts screaming like mad immediately.
DD has 3 hrs 15 min A times between every nap and before BT, naps are usually between 40 min or 1 hr 15 min.
What can I do to get her back to sleep quicker or avoid that she wakes up at 3.30? It's quite hard on both of us and I can see that she is so tired in the morning after that big interruption at night.
I would be very grateful, if someone had some ideas!

[Erin M]

I think she probably needs some more A time -- when babies are up and wide awake for longer periods of time at night, it generally means they need to be awake longer in the day in order to balance it out.  At her age, you can have an A time range of all the way up to about 4 hours, so I'd bump it out a little bit over the next few weeks and see where it gets you -- especially since you're getting shorter naps -- it should help you there too.