What was the first appearance for the character that Bella Donna Boudreaux is commonly associated with?
Bella Donna (comics):  One of these characters is Bella Donna Boudreaux, commonly associated with the X-Man Gambit. Gambit (comics):  Drawn by artist Mike Collins, Gambit makes his first appearances in "Uncanny X-Men Annual" #14 (July 1990) and "Uncanny X-Men" #266 (August 1990).
"Uncanny X-Men Annual"