Adding gmail

I got my 11-year-old daughter and iPad. I set her up with a new Apple ID. Her Apple ID has an email with an @iCloud.com address. This is what shows up under the Mail icon on the iPad. I want to add her school email address in for her. On my iPhone Under settings-mail there is a button that says “add account”. On her iPad under settings- mail that same “add account” button is not there. Does this have to do with the fact that she is 11 and so we have her account set up under the family sharing? Am I doing something wrong? How can I make it so she doesn’t have to download and look at at it in a separate gmail app?