Honestly, I haven't had this happen that I can recall, but...What a doctor might ask is: Is there anything she's around during this time that could be the cause of it? You have to consider ANYTHING she touches. Certain toys, a new laundery detergent used, a new toothpaste/shampoo, etc. Is there a stuffed animal that she only sometimes plays with? She may actually have to see an allergist to be tested for certain things to find out. Sometimes it can be a new soap (which could have been used to wash a toy or something). Perhaps you could wash all her toys in order to "start over" and then the next time you notice these things, pay a little more attention to EVERYTHING that was around her in the last 24 hours. As best you can, of course. I would hope that her biological mom would be willing to help with this sort of thing. I hope this helps some. My girls are older, so it's been a while since I had to deal with the "little" ones. =) If you do find out, share with us so we might learn as well.