One of the first country-blues pieces I wanted to learn was Mississippi John Hurt's "Richland Woman Blues," a song whose lyrics come from a a woman's point of view. I always took the attitude that the male singer (whether Hurt when listening, or me when practicing) was telling a story by delivering an extended quotation.

MJH's "I'm Satisfied" also seems to be coming from a female's point of view, although it's a bit more ambiguous than "Richland Woman."

I sing both of 'em without hesitation and without explanation.

There are songs where a "gender change" seems more necessary and where such a change is also easier to achieve ~ straightforward love songs wherein it's a simple matter to change "him" to "her," etc. Is those cases, I'll do it. In songs like the abovementioned where the lyrics present a more complicated scenario, and where a quick change of a few words won't help and won't make sense, I'll do what singers have done since time immemorial: just perform the song as-is.

I don't think it's a question of how old or "traditional" the song may be; I think it's just a matter of whether the gender readjustment can be accomplished easily and effectively without changing the song too noticeably.