The Girls Aloud bandmates are said to have been in regular contact since Sarah entered a centre in Arizona to get help for alcohol addiction and depression. They are hoping to take a break in the US once she is fighting fit.
'Cheryl has been there for Sarah massively,' said an insider to The Sun.
'They've had some heartfelt conversations on the phone. Cheryl can identify with Sarah because she's hit rock bottom in the past too.
'It's been a long time since they've spent real quality time together so they've decided to jet off for a break.
'They thought America will be best as they can slip under the radar easily out there. Obviously it will be a wholesome holiday.'