Yes, she is a girl. Let's leave the mutation aside for a while... If i were you i would be more conserned why the baby is missing his main flight feathers...
Have you cut them?
If not... In case that baby comes from a nest where most of the other babies hatched and died after a week and the surviving babies have lost their main flight feathers that could mean your budgies have Budgie Fledging Disease (also known as Avian PolyomaVirus) which is highly contagious. Have you bought this or was it raised in one of your nests?
Looks like a girl, hard to tell from the picture if she's sky blue, violet sky or cobalt - combination pied, opaline, possibly greywing or clearwing
What a cutie!
Thanks! I think she's a super cutie too. I'm madly in love with her (even if I had originally wanted a male). Her blue is more on the cobalt side but it's not very dark. I love that she's a mutation grab bag. She's so pretty. When she moults, could she end up with even more blue spots or other markings?
We're on day two of her letting me pet her tummy with my finger. I think the taming process is going well!