Hey Antonio, and welcome to planDisney!
How sweet is it for your mother to be visiting her grandson for the first time! The image of that meeting makes me smile for sure.
There should be no issues with your mother using her 6-day ticket, as all unexpired theme park tickets with remaining admission days are honored. To get the assistance she needs with linking her theme park ticket to My Disney Experience, she will need to call 407-939-1289 to speak with a cast member. In addition, she can check with
Guest Relations at the theme park when she arrives.
To ensure that she is included in your plans, you will want to add her to your
Family & Friends List, and once her tickets are linked to her
My Disney Experience account, you will be able to include her in all of your plans.
Please let us know if you need additional assistance prior to your arrival date; we are here to help.
Have a magical gathering!
Raquel