Published Friday, 15 June 2012
The former Zoey 101 star, 21, performed the tune I Look Up to You onstage on Thursday 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 world/You've outgrown your room, it all happened way too soon/They took away your innocence. We forgot our strong defence."
The Toxic hitmaker famously suffered a public meltdown in 2008, when she was hospitalised and placed under the conservatorship of her father Jamie.