Georgie and Mandy have been through a lot together, including the arrival of their daughter, Baby Ceecee.
Mandy's character was never in The Big Bang Theory, allowing Young Sheldon to create a unique story for the couple
Mandy applies to be Medford's local weather girl, attempting to re-enter the workforce after having Baby Ceecee.
Georgie tries to dissuade Mandy from pursuing the job, causing tension in their relationship
Georgie doesn't understand Mandy's desire for a career, believing that he can provide for their family.
In The Big Bang Theory, Georgie creates a successful tire empire but still doesn't understand Mandy's career aspirations
This difference in perspective may ultimately lead to Georgie and Mandy's breakup, as hinted in Young Sheldon S6E19.