Family Sharing & Purchases

How can I set up family purchases so that minor children can not purchase apps etc. which will be billed to my credit card? Currently we are using Family Sharing and my credit card is the only payment method.

If I turn off family sharing, then we can't share music and apps purchased by others in the family. Is there a way to assign a certain balance to each Apple ID and still be able to share purchases? Or am I forced to use my credit card as the only billing method for the family?

My pre-teen daughter recently downloaded two apps offering a "free 3-day trial" not realizing that a weekly subscription was attached (unless the subscription was cancelled within the 3-day period). Each app began billing us $10.49 weekly and by the time I caught the issue a total of $71.00 had been charged to my credit card for purchases I didn't authorize as a parent. Is there a way to control her spending without using the "Ask to Buy" option under family sharing?

Any help or advice the community can offer would be greatly appreciated.