The singer - who recently claimed she had not spoken to Cheryl Cole, Sarah Harding, Kimberly Walsh or Nicola Roberts in some time - said although she didn't miss them when she was recording her solo album, she sometimes finds herself looking around and wondering where the other girls are.
She told MailOnline: "With the Girls Aloud studio process we always went into the studio by ourselves. I've always been in the studio alone. So the recording wasn't really any different.
"It's now when it comes to doing this stuff - interviews and things that I'm thinking I need more people around, I think 'ahh, where are the girls?'"
Nadine also revealed that her four bandmates sent her "a really big, really beautiful" bouquet of flowers to congratulate her on her engagement to American football star Jason Bell.
The Northern Irish singer added that while she and Jason had discussed marriage before he proposed she still can't get used to having a fiance.
She said: "He made absolutely sure. He asked me what kind of diamond I wanted. He sent me a website and I had a look and found one I liked. The proposal was an ongoing thing which made it more exciting.
"But I still call him my boyfriend.
'He says, Nadine - fiance', and I'm like, 'oh, that's right."'