Daughter unable to make purchases on Toca World using Family Sharing

My daughter has an iPad which is linked to my account using Family Sharing. When she wants to download a new app I receive a notification to either allow or deny but for some reason when she tries to purchase an item from the shop in the Toca World game this does not happen & she is unable to do so. I cannot work out what the issue is & don’t know how to make it work. Any ideas?