why my daughter can't have apple pay?

Apple requires you to be 18 or older to be able to have apple pay. Unfortunatley theres not really anything that you can do to have someone under 18 to have Apple pay. Personally speaking you could just set her up with a Venmo, because it seres the same purpose.

Hello ~ If she is 13 and has a supported credit card she can…if this is Apple Cash she must be 18. Take a look here:

Set up Apple Pay - Apple Support

Set up Apple Pay Cash and person to person payments - Apple Support

It may also have to do with where you are located as well.

~Katana-San~