Complex sentence: She also released her first album, titled "Santa Claus Lane" which was a collection of Christmas songs which included duets with her sister, Haylie, Lil' Romeo, and Christina Milian.
Split into simpler sentences: She also released her first album, titled "Santa Claus Lane". The album is a collection of Christmas songs that includes duets with her sister, Haylie, Lil' Romeo, and Christina Milian.