If it's just a hairstyle, just buy a mirror and change it (you can also choose makeup)
Babies who can't walk will need teenagers or adult villains to pick them up first, change them and then go to the camera.
There will be an option to "change the appearance of ..."
Remember, some mirrors don't support changing hair style/dressing, only support training charm.
So if you can't change it, try more mirrors.
If it's appearance, you have to use patches to force plastic surgery.