Apple.com Charges

New iPhone 11 Every month have charges of $100 to $200. It's my granddaughter's phone so I don't have direct access to it. She said that she only wants to have the Apple Music which I believe was $9.99 a month. Every time she gets a new device the old subscriptions pop up without our knowledge until the monthly statement comes in. In the past I believe she just deleted the apps but I read that is not enough to stop the subscription. Any advice is appreciated as I can't afford this.