[spiralx]

> Is she predisposed to be okay with cold climates, or was she born so that her parents could handle the cold?

The second meaning doesn't make any sense, you could say "I was born to fulfil this destiny" for instance, because there's only one subject in the sentence, the singer.

> Romantic love or parental love?

"I'll be your X" is a clear indication of romantic love...

> Is she saying the last line, or is it her parents talking to her?

Where do her parents come into this? There's no ambiguity at all here: the singer isn't asking much of the person they're singing about, only that they sing along with them.

Given that the song is about famous country and western stars, two of which were married while the other two almost became a couple but one died before it might have happened, it seems like you've read ambiguity into it where there isn't any, and used it to fill in your own interpretation. Which I'm sure we all do at times.