Chris Brown's daughter paid Selena an adorable tribute, and the late singer's family couldn't be prouder.
Selena's brother, A.B. Quintanilla, tells TMZ he was moved when he saw Royalty's Halloween getup -- a glitzy purple jumpsuit like the one Selena made famous in a 1995 Houston performance ... just a lot smaller.
A.B. tells us, "I think it's beautiful that of all the Disney characters, princess and superheroes, she picked my superhero." He also gave props to Chris, saying ... "you have an adorable daughter."
He should've shouted out Nia Guzman -- we're told Chris' baby mama chose the costume because Royalty was born in Corpus Christi ... Selena's hometown. Plus, Nia's a huge fan.
We're told celebrity designer, Robyn Thicck, put the outfit together.