Jewel has admitted that co-parenting with her ex-husband is not always easy.

The 41-year-old singer split with rodeo cowboy TY MURRAY, 46, in 2014 and the couple have been working hard to ensure that they stay on good terms for the sake of their four-year-old son Kase.

She told PEOPLE: ''It's work. I don't want people to think it's effortless - it's work to do this because you obviously don't get a divorce because things are going well. But it's letting those things live in the past.

''It means realising you're in a relationship forever, so learning to treat one another with respect and dignity and just doing the right thing for Kase.''

Meanwhile, Jewel previously revealed that she and Sean Penn ''fell in love'' while he was on a break from now ex-wife Robin Wright.

Jewel claimed she and the Oscar winner, who had an on-again, off-again relationship with the 'House of Cards' actress until their divorce in 2010, had a passionate romance in 1995.

Recalling their first encounter in her memoir 'Jewel - Never Broken: Songs Are Only Half the Story,' the blonde beauty revealed: ''He had seen me on 'Conan' and was working on a movie he'd written called 'The Crossing Guard'. He wanted me to compose a song for it. I told him I would and he said he would meet me anywhere to screen the movie, I could name the day. I gave him my cell number and figured I would never hear from him again.''

But their friendship blossomed into something more after Jewel wrote the track 'Emily' for the movie.

She added: ''We spoke on the phone a lot and he was a fantastic flirt and I did not mind one bit. But I was no fool and knew I was most likely a trifle to him. I intended to give him no such conquest. I put that man through his paces and he took it in stride. He began to court me in earnest, following me around on tour, acting as my de facto roadie.''