Here is a review of a couple individual songs:
My Humps: Just from the title, you should realize the explict-ness of this song. Lyrics include: "I'm gonna make you work", "What'cha gonna do with that junk in your trunk", and obviously more explict stuff. "Lovely lady lumps" isn't the best thing for a 9-year-old.
Don't Phunk With my Heart: "Phunk" is obviously used as a form of "f*ck". Lyrics include but are not limited to "I love you more than s*x appeal".
Pump It: I didn't hear any explict material in this song.
However, the tunes here are kind of catchy, so if lyrics are unaccounted for in your family, this should be just fine for you and your family.