Hi,
I don't have any advice, but whatever you decide to do will be right cuz your her mom. I hope she feels better soon and it's nothing serious. Maybe she had a sliver or a piece of glass stuck in there and it's infected. I don't think it would have anything to do with the mange, but who knows I'm not a vet. Maybe phone the clinic and ask them what you can do until you can get to your vet.... Good luck
Jodie