Credit cards are dangerous, can she get rid of them and use a debit card instead? (not sure you use the same word as us in the UK but I imagine so?) then she can still spend money but won't actually owe it because you can only spend what you have in your account.
Does she realise it's an actual 'problem'? She's admitted she's doing it for emotional reasons, not that she needs to buy these things, but does she realise that it's a problem and causing her to get in more and more debt? It could get WAY out of hand if she carries on.
Sorry I don't have the solution. I think your mum has to seek help herself. This is a lot for you to deal with and with you being quite young it's hard to sit your mother down and give her a talking to!
I hope she can realise she has a problem and seek help/change her behaviour. Maybe if you told her how worried you are about the money etc.
x