oh, I made a mistake.
It should be :
The lyric of Ella's song is written by Selina.
Hebe wrote the lyric of another song.
Ella's song is called "Lao Puo 老婆" which means "wife" (that's how they address each other)
Hebe's song is called "Shuo Ni Ai wo 說你愛我" (Say You Love Me)