The actress said that Apple, six, and Moses, four, had no idea what she and husband Chris Martin did for a living until their school chums told them.
She told The Sun: 'My kids have never seen me in anything. They don't know what I do - or rather, Apple does now because people in her class know and they say, 'Oh, I saw you in a magazine'.
'And you're like, 'Oh God. I'll have to deal with all these questions that will inevitably be coming', but I try to separate it.'
And after her tireless guitar rehearsals for Country Strong, she admits that her children think she is a singer rather than an actress.
'They know I work but they think I do singing, which is hilarious,” she said. “They probably saw me for a year practising my guitar and singing and they think that's my job.
'They know I'm in movies and stuff, but I don't think they really fully get it.'