The star returned to singing after being away for three years during which time she had two children, Ethel and Marnie-Rose.
But she told Elle magazine: "I wanted to concentrate on making a family. I've done that. I love that. I thought I'd be better suited to that.
"I love my kids and I wouldn't trade them in for anything – no mother would – but I'm not the sort of person who can sit at home and look after them all day. There was a void. I'm a creative person, I like to speak my mind. Making music is the perfect vehicle for that."
She gave hints of becoming frustrated with looking after her children - two-and-a-half-year-old Ethel and Marnie Rose, one - full-time as long ago as last March when she Tweeted: "I'm bored of changing nappies and cooking dinner."
In the Elle interview, Lily also confessed to having insecurities about her body and looks – and said she'd like to look like 40-year-old model Kate Moss.
When asked about the universal pressure to conform to stereotypes, she said: "Of course I'd rather look like Kate Moss than look like myself."
She added: "I wish I didn't feel like that and I think the reason we feel like that is because of the imagery we're fed all the time.
"Women are still expected, in some weird way, to kind of sit there and look pretty, and not talk.
"So often, when women say things that are outspoken, or as I call it just saying things, people jump on that and try to make us look stupid for having an opinion. That doesn't happen with men. Come on, we've done feminism. People are aware of it. Can it just happen now?"
Lily and Kate used to be good friends and were seen partying in St Tropez in 2009, but the singer snubbed the model when she didn't invite her to her June 2011 wedding to builder Sam Cooper.
• See Lily Allen's full photo shoot and interview in the March issue of ELLE on sale 30 January 2014.