Adeleine is a character very similar to Ado. Like Ado, she is a human painter. Her first, and as of yet only, appearance was in Kirby 64: The Crystal Shards for the Nintendo 64, where she was possessed by dark matter and then had to be freed by Kirby. Once Kirby was able to free her, she traveled along with the protagonist throughout the rest of the game. She'd help him out by painting many items which would then become real, such as health items.
Its very likely that Adeleine is actually Ado herself. Her name is japanese is Adoreenu, meaning that the likely nickname for her would be Ado.