Britney Spears' little sister Jamie Lynn has debuted a new song all about her admiration for the pop superstar.

You can imagine who I wrote it about

The former Zoey 101 star, 21, performed the tune I Look Up to You onstage on Thursday (14Jun12) at a show in Nashville, Tennessee, and introduced the country ballad by telling fans, "You can imagine who I wrote it about".

In the opening verse, Spears sang, "Saying scared little girl living in a big old worldYou've outgrown your room, it all happened way too soonThey took away your innocence. We forgot our strong defense".

The Toxic hitmaker famously suffered a public meltdown in 2008, when she was hospitalized and placed under the conservatorship of her father Jamie.