Dog thinks her toy is a baby?

I took my 3 year old chihuahua to visit family last week. She was spayed at 6 months old, and never had a litter of puppies. Anyways, my parent's dog had a litter of pups (the pups are 2 weeks old). We spent a couple of days there, and Isis (my chihuahua) kept trying to get into the whelping box to see the pups. We have been home for 3 days, since we have been home, she has been carrying her stuffed monkey around, trying to find a place to hide it, whining, and has taken to sitting on my bed with the toy all day guarding it from our other dog. Should I take her toy away? She has had this toy since the day I brought her home at 8 weeks old, and has never done this before.