Not crying when waking up

Anyone else have a child that doesn’t cry when they wake up in the middle of the night or for naps? My 12 month old has been doing this for a little over a month now and it’s driving me nuts. She wakes up and just sits up and starts playing with her blanket or stands up at the side of her crib. I have no idea she’s awake unless I happen to look at the monitor.

I don’t really mind naps but I don’t know how long she’s awake at night before I realize she’s awake which then makes it harder to get her back to sleep. Occasionally she’ll babble and that’s what wakes me up and she’s wide awake when I go in and ready to play.

If your child did this, was it just a phase? How long did it last? Did you do anything to help them?