I think it's silly.
I once worked with a Jande, pronounced JAN-dee. That was her full name and not a nickname. So of course I had to ask her how she received this unusual name. She said her mother coined it as a combination of her own name,
Jamie, and her favorite name,
Amanda. Then Jande made a remark along the lines of her mother must have been on drugs.
Anyway point being, I prefer Jande to Dandie.