How can I use family sharing, but allow my daughter to purchase with her iTunes allowance without asking permission?

Question

I love the idea of iTunes family sharing, but I don't think it currently supports my situation.
My daughter's iTunes account gets a monthly allowance (plus occasional gift cards), and does not have a credit card tied to it. That way, she can buy whatever she wants, but only with her existing account balance.
I'd like to tie her account to mine via family sharing, but want to keep her spending limited to just her allowance balance. Also, I don't need to grant permission each time she wants to buy something when using her balance. Ideally, she would be permitted to buy exactly as she does now (no permission necessary, no credit card on the account, and only using allowance funds), but also be tied my family account to listen to music I've already bought.
It appears that my 3 options are:
Do not do family sharing and keep the accounts separate.
Tie the accounts together, put "ask to buy" on her account, and then get bugged for permission each time she wants to get something (as well as keep track myself of her going over her allowance and dipping into my credit card).
Tie the accounts together, don't use "ask to buy", and keep my fingers crossed that she doesn't spend more than her allowance amount (because iTunes would permit spending more than that and charge my card).
Options 2 and 3 don't work for me, and option 1 doesn't take advantage of family sharing.
Can I have a family sharing account that *doesn't* charge to my credit card?

Answer 1

Hello jeffchr,
Thanks for the question. Based on what you stated, it seems like you don't want to be billed for a family members purchases. I would recommend that you read these articles, they explain the features options. 
Family Sharing
All new iTunes, iBooks, and App Store purchases initiated by family members will be billed to the family organizer’s account.
Family purchases and payments
Making purchases
After you set up your family, any time a family member initiates a new purchase it will be billed directly to your account unless that family member has gift or store credit. First, their store credit will be used to pay the partial or total bill. The remainder will bill to the family organizer's card.
How iTunes Store purchases are billed
Which payment methods will be used first?
When you make a purchase, content credits are used first, followed by Gift Certificate, iTunes Card, or Allowance Account credits. Your credit card or PayPal account is then charged for any remaining balance.
Thanks for using Apple Support Communities.
Cheers,
Mario