Jewel initially turned down the chance to play country music legend June Carter Cash in a TV movie as she feared the risky role would "probably ruin" her career.
The pop star was approached to play Johnny Cash's second wife in new biopic Ring of Fire less than a year after giving birth to her son Kase in 2011, and Jewel admits acting was the last thing on her mind.
She urged bosses at TV network Lifetime to find another actress, but producer Jonathan Koch was convinced she was the right woman for the job.
Jewel tells Billboard.com, "It sort of stunned me, as I had a baby about eight months before, and had no plans of acting. I tried to talk him (Koch) out of it, but he seemed very determined to have me. I told him I would probably ruin my career, but he wanted me to do it anyway.
"The reason I accepted it was that it was such a challenge. I did a lot of acting a long time ago in (1999 drama) Ride With The Devil with Ang Lee, and had read a bunch of scripts after that. It was usually the girlfriend of somebody, and really not that interesting, when you have a full time career and the demands of that. The script for this was one of those rare chances where you actually had a real dramatic role. There were a lot of highs and lows with it, and it was such an opportunity. I was excited to see if I could do it or fail."
Ring of Fire, which will air on 27 May (13), also features former Six Feet Under star Frances Conroy as Mother Maybelle Carter, while Matt Ross plays Johnny Cash.