The former Girls Aloud star claims the 30-year-old 'X Factor' judge - who split from ex-boyfriend Tre Holloway last year - is ready to have kids, but for now they are both happy looking after their pet dogs.
Sarah, 32, told The Daily Mirror newspaper: ''I know that Cheryl is broody, but we both have our animals.
''Maybe I should think about having kids at my age, but i'm still young and while I do want them one day, right now I don't even think I'm responsible enough.
''I've got my dogs and I have my godchildren - three boys of three, six and nine. They are my baby fix for now. I will probably get more dogs and other animals before I have kids.''
Sarah - who lives in Buckinghamshire with her DJ boyfriend of 18 months Mark Foster - admits she doesn't want to ''leave it too late'' and will have kids by age 35, but is ''over the moon'' for her bandmates, Nadine Coyle, who welcomed a daughter with boyfriend Jason Bell in February and Kimberly Walsh, who is expecting a baby with partner Justin Scott.
Sarah gushed: ''Kimberley texted me a couple weeks ago and she is so excited. She is going to be a great mum, she and Nadine are so family orientated.''
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