Cheryl Cole says Kimberley Walsh is her "safety network".
The pop star insists she is close to all her Girls Aloud bandmates but always goes to Kimberley if she has a problem because she will always give her a hug.
Cheryl - who has endured a tough 2010, splitting from her soccer player husband Ashley Cole and contracting potentially fatal disease malaria - said: "I have a lot of amazing friends, but the girls - Kimberley, Nicola (Roberts), Sarah (Harding) and Nadine (Coyle) - they're like my sisters because we've been through so much together for so long. They just become your best friends. But Kimberley is my safety network, she's the one that gives you a good hug when you need it."
Despite the turbulent last few months, the 27-year-old singer insists she has taken a valuable lesson from the upheaval in her life - to live in the moment.
Referring to her hit single 'Promise This', Cheryl said in a video interview on YouTube: "I promise to take each day as it comes, that's what I've figured out. You just have to live each day and live in the moment instead of worrying about tomorrow. I'm always thinking about next week or next month but I need to live in the day."