Linda Flynn-Fletcher

Phineas and Ferb: Forever Summer
She and all the other characters are older and the setting is in the future in this series. She also becomes a grandmother, as her daughter has her first child, named Amanda.

Phineas and Ferb: A New Beginning
Phineas and Ferb are now in there twenties and Candace is in her thirties. Candace is married to Jeremy and has a little girl Amanda, Ferb and Emily Kinney get married, which Linda becomes the grandmother of their children Thomas Fletcher, Elizabeth "lizzie" Fletcher, and David Fletcher. Also, Phineas and Isabella get married and they have two daughters named Julia Flynn, and Lynnette Flynn. Also, they have a son named Adrian Flynn.

The Annual Troop Olympics
She is mentioned to have been in the Icesmoke Troop when she was Phineas's and Ferb's age.