How can I approve "ask to buy" purchases my daughter makes on her ipad without an apple device?

My 11 year old has a new ipad. I don't have an apple device, I have an Android phone. She is trying to download apps and I would like to approve them, but I don't get any "ask to buy" notifications. What can we do? She has tried downloading an app so many times and we no longer get "approve on this device" as an option. I do not want to sign in on her device and give her full access to my account- I have already learned the hard way why this is a bad idea, and it's partly why she has her own device.