"Dada" is big brother in Reunionese creole. Actually, it can be used for really any older child. This is Victor, Maitena's real older brother, (Fabrice's first), but we use "Dada" for her older cousins as well. It's generally a term used among children, but Fabrice's sisters for example (both younger than him) still refer to him as dada.

Victor has only spent a couple days so far with Maitena and the road towards being a proud older brother has been well established since before she was born. (We used to say "when Maitena arrives we're going to do this... when Maitena is here you can show her how to... etc.). However there's quite a bit of complex emotions to work through (jealousy being only one of the normal reactions to the only-child-to-dada transition).