Lynne Spears' heart "broke into a million pieces" as she watched her daughter Britney's breakdown on live TV.

Britney Spears suffered a public meltdown in January when she was involved in a three-hour stand-off with police after refusing to hand back her son Jayden James to ex-husband Kevin Federline following a scheduled visit.

The Toxic hitmaker's mom - who at the time was estranged from Britney - saw the drama unfold on TV, and admits the events left her emotionally pained.

Describing the incident in her forthcoming book Through The Storm - A Real Story of Fame and Family in a Tabloid World, Lynne writes, "It was so shocking, so disturbing to see that girl with such despondency in her eyes - it broke my heart in a million pieces."

She adds, "(Britney) refused to speak to me, and our estrangement lasted an excruciating seven months."

The star has since rebuilt her life under the close watch of her father Jamie Spears, who was handed control of Britney's estate after she was hospitalised for a psychiatric evaluation in a second incident at the end of January.