How long is her pregnancy?
Ask your presumably human mother.
Also looking at the wiki entry, she was supposed to go to Nursery and I was supposed to be able to rub her belly, but only preggo content I've seen were her morning sickness scene and her protecting her stomach when I wake up after cuddling. She's currently 96 days pregnant on my ship.
IIRC the option to rub her belly shows up after 110 days. She only demands to go to Tavros after about 200.