Hey Staci ~

You and the Folks should check with you own Cell Companies ...

Ask How Much? to ADD a "second family member" to your accounts.

Some companies will add an additional phone and number for as litttle as $10 / month -
and give you additional minutes that are shared between the phones.
The extra phone is usually "free" or less than $30 to buy.

You may have to "fib a bit" about her relationship and/or her address ...
but maybe your Daughter Keegan can just "loan" her new phone to GranMom.