Stumped about mouse crying

Question
Natasha,

I forgot to ask you because the little girl is half fancy half mouse will she hurt the mommy who is just a Fancy Mouse?

From time to time I hear them yelp, but it just sounds like they are playing.  But I notice that the mommy mouse when they are sleeping- always they are together when they sleep like they are hugging each other. but many times the mommy is sleeping but it almost sounds like she is crying. They aren't fighting they have two tanks and two food bowls so they never fight over food ever and 4 wheels. It breaks my heart because she is in a deep sleep and I tap on the little walk around to see if she is ok. she looks at me like why did you wake me. This happens almost every day. Is she missing her kids? The little daughter is sound a sleep so I know she isn't hurting her. Is she depressed, her son's are in the same room but they can't see each other, should they? When she is up she is always biting on the door to the cage. she can see the little mouse that I think is a little girl but I separated because i thought he was a boy. Yikes help me sort this out please.

Answer
Hi Leah,

I haven't answered because I am stumped! So I am asking a bunch of my mouse breeder friends.  So far they are stumped too, but I just sent the question to three more people!

Is it possible for you to get a video and  post it somewhere you can give me a link? Are you on Facebook?

There is the possibility that it is pain or the beginning of a respiratory infection, so there may be a vet trip in the future for her.  

I will get back to you soon. I am sorry to keep you waiting.

squeaks,

Natasha