Kimberley Walsh may soon become a mum.

The 31-year-old star's former Girls Aloud bandmate Nadine Coyle recently became the first member of the chart-topping girl group to get pregnant, and Kimberley expects that she and boyfriend Justin may be next in line to embrace parenthood.

She admitted to new! magazine: ''It won't be long.''

Earlier this month, Kimberley revealed that she and Justin - her boyfriend of 10 years, who is already a father - were ready to have a baby, but that they do not intend to get married any time soon.

She said: ''We're not too bothered about the whole marriage thing ... I just think whenever it happens for us it'll be the right time ... It's still pretty good after 10 years, we try to keep the fire alive.''

The singer is bound to have natural maternal instincts as she has already acted like a mother figure as the oldest member of Girls Aloud

She said: ''[Motherhood is] natural and obviously something I give off. I really felt a sense of needing to look after Nadine and Nicola [Roberts]. They were 16 and I was 21 and there is a massive difference.''

Kimberley admits she was surprised by Nadine's pregnancy, but looks forward to meeting her little bundle of joy.

She added: ''I'm looking forward to seeing her as a mum because I think it will change who she is quite a lot because it is a big change in someone's life. During the [Girls Aloud greatest hits] tour, as she said herself, it wasn't in her brain. But sometimes when that happens you realise it's what you want.''