Well, i think that ppl are getting too worked over a game, as a dwarven fantasy life simulator, i don't think the whole "oh my god, that's so offensive" status is reasonable.
Dudes are killing eachother with axes'n'all, they really aren't into that whole discussion, it's a medieval fantasy, i think the society tags thing are a great idea, since i doubt that elfs, humans and dorfs would have standartized cultures, as in DF at the moment (and in general dorfish fantasy knowledge) Dwarvenkind does not diferentiate themselves by sex as humans do, they prize effort and deeds over gender.
Dwarven women that realized something great or was known for that should and would name a bloodline, so i think that legendary or accomplished dwarven individuals should start a bloodline. The hammerlord dorf that killed a squad of gobbos should name a bloodline, no matter if male or female. Dorfs seem (in general fantasy settings) to respect females very much, usually saying that dwarven women are fiercer them hell itself.
Returning to the topic, i think only Legends should start a Bloodline, maybe using the same Surname or adding a "descendant of Urist McUrist , the slayer of dragons" or "son of Urist McSmith, Legendary Smith/ Creator of AdamantineAxeofDoom".
That seems to be an easier task as new name trigger could just be applied to replicate on the family members (wife and offspring) to add the [BLOODLINE] tag, adding the legendary fact (for jobs/moods and slayer of [insert biggest killcount here]).
Dunno, what do you think?