Kimberley revealed that is expecting her first child with long-term boyfriend Justin Scott on her Twitter page back in February, and has now recalled telling her close pal Cheryl the happy news.
Girls Aloud BFFs Cheryl and Kimberley
She told OK! magazine: "Cheryl burst into tears of joy when I told her I was pregnant."
Cheryl, who Kimberley remains good friends with despite Girls Aloud splitting last year, was among the first stars to congratulate Kimberley on her pregnancy on Twitter.
Kimberley also proudly showed off her baby bump in London on Monday night when she attended a performance of 'From Here To Eternity', but it was actually her arm that got people talking.
The singer was photographed with her arm in a sling after falling over and breaking her wrist, the first time the singer says she's ever broken a bone.
Kimberley showing hints of a baby bump, but our eyes are drawn to her arm
She tweeted on Sunday, following a trip to A&E:
Kimberley also opened up to OK! magazine about her first scan, saying: "I saw the baby wriggling away and burst into tears, crazily so. It suddenly felt real and it mustn't have done until that point.
"I was overcome with emotion, I don't know where it came from."
She also said that she won't be finding out the sex of the baby, explaining that she would prefer to be surprised.
Read the full story in OK! magazine, out now.