How to pay for app subscriptions for teenagers?

yelf

My daughter is 14 and so does not have a bank account to pay for apps etc. Her phone account is not a child's account as apple stop child accounts at age 13.
How can I pay for a monthly subscription for an app that I can control the cancellation of subscriptions for? 
I know I can cancel from her phone but its not that easy due to certain reasons that I won't go into.
Currently her mum has linked daughter app store to mums bank account but that means there is absolutely no way that mum can cancel the subscriptions without doing so via daughters phone.

Any help would be great 

Vitor

Tricky when there's issues that prevent Family Sharing on an Apple Account. I'd suggest either using an Apple Gift Card which, while it won't allow you to cancel the subscription, will cap the spend or look at a Prepaid Virtual Debit Card for teens such as Revolut <18 so you can freeze the card, set spending limits, or monitor transactions.

RavingMad

Which app are you thinking of? Is there a website for the app in question? We pay for Spotify and Omniplex pass for the daughter but can cancel through the website rather than the app

yelf

Unfortunately her mum has already set the subscription up from the app

mksysb

Get her a Nimbl card, you then have an app on your phone which can control what she spends.

https://nimbl.com/