You realize you just repeated the same origin I gave, minus the Superman marriage.
And no, so long as the character has a backstory it's always going to be there. You're basically asking everyone to just jam their fingers in their ears and yell "LALALALALALA! Linda's origin isn't ridiculous or convuluted!" But it's there.
Linda being Flamebird would be a joke. Just one more thing on a pile of things that Linda is/was, which was a protoplasmic Lana Lang dead girl Earth born angel of fire. I don't think you need to tack more on to that.