You can delete an email account from the Mail app by tapping on the account id in Settings > Mail, Contacts, Calendars and then tapping 'Delete Account'- if that is where your contacts are coming from then when you delete the account you should get the option as to whether or not to remove the account's contacts. If multiple email accounts are still on the iPad after that then you can set the default account for new emails via Settings > Mail, Contact, Calendars > Default Account.
For Messages if the iPad is using your account then Settings > Send & Receive, tap on the id at the top of that screen and sign out of it. She can then sign in with her own account.