I set up an icloud id for my 12 year old Daughter on Family sharing, the main reason for doing this was so that she could have an e mail address, how can she access her e mails?

Hello Gmac8,

Thanks for using Apple Support Communities.

When you create an Apple ID for a child for use with Family Sharing, it is also creating that Apple ID as an iCloud account. This allows you to share things in Family Sharing like the Family shared calendar for example. She will just need to login with the Apple ID and password, same as anyone else, on iCloud.com.

Family Sharing and Apple IDs for kids - Apple Support

Take care,

Alex H.