Ghosts?

The last several days we've been having a very hard time getting Nyla down for naps and bedtime. She begs and begs to sleep in our bed and cries bloody murder until either I give in or she falls asleep.  A few minutes ago, Nyla (28mo) was on the changing table where she calmly explained to me that there was a girl in her room who was waving at her. Here is word for word what she said:

Nyla:"Mommy there is a girl in my room".
ME: Where?
Nyla: She was over there (pointing to an area next to her dollhouse)
ME: Is she there now?
Nyla: "No, but she scares me. She was waving at me".
ME: When?
Nyla: "When I was in my crib."
ME: Is she happy or sad?
Nyla: "Sad".
ME: Is she ugly or pretty?
Nyla: "Ugly".
ME: Is she mean to you?
Nyla: "No, she's not mean, but she scary to me"
ME: "Does she talk to you?
Nyla: "No, she waves at me". She couldn't help me get out of my crib. She scary to me. When I go to your bed she can't wave at me."

I RAN downstairs to write this down so I wouldn't forget her exact words.  I figure we either have a ghost or a VERY clever and imaginative 2year-old!!  Either way, how can I deny her my bed after hearing THAT?

Update 8/22-5:18pm-While changing another diaper Nyla said, "Mommy, I'm scared of the girl that waves at me. When she goes back to her own house, I can sleep in my crib".  I purposely have made no mention of  "the girl" and in fact tried to talk about other things while in her room to keep her mind off it, but she brought it up a second time.