D17 taking the card is obviously inappropriate. Maybe have her work off some of the charges or some other appropriate lesson. And make sure she understands boundaries for the future.
As for who will pay for all the applications, that's something to work out with STBXW. You can't dictate how she spends the money unfortunately. And these applications are not part of the normal expenses that the child support is calculated to cover. Perhaps you should counter that you will pay half if she'll pay half? Or you'll pay a third, STBXW can pay a third, and D17 can pay a third?
Hope you guys can work something out soon.
Hang in there.
Michelle - Proud DR Rockette S: 28JUL07, D'd: 29OCT09 http://tinyurl.com/27j9qo2