It sounds like your financial priorities are different. She wants to be financially stable, and you want to live in the moment. Neither is bad, but you do have to come to some sort of compromise and agreement to end the friction on the matter.
These financial tips from others with ADHD might help too:
Penny
ADDitude Community Moderator, Parenting ADHD Trainer & Author, Mom to teen w/ ADHD, LDs, and autism