Harding had to go rehabilitation after breaking up with DJ Tom Crane in 2011 as she struggled with alcohol and sleeping pill addiction.
However, her band mates Nadine Coyle, Nicola Roberts, Kimberley Walsh, and Cheryl Cole are working hard towards her recovery, reported Contactmusic.
"The girls are really looking after her. Sarah has put a lot of effort into her recovery and the band want to be fully behind her if she feels low," a source said.
"The girls have tried to make sure Sarah spends nights on her own doing yoga and relaxation techniques before bed, so she can sleep without resorting to pills again," the source added.
The band has recently made a comeback and gearing up for new album and tour next year.
