Legally, a married woman WILL be referenced with her husband's last name, whether or not she chose to take it. If Miss Doe marries Mr. Smith she will be called Mrs. Smith by numerous people, regardless of whether she decides herself to be called Miss Doe still, or Mrs. Doe-Smith, Mrs. Smith-Doe, or even Mrs. Smith. So I find it useful to make sure the husband's name shows up somewhere on her record as it's likely that somewhere in her married life, she was referenced that way. There are exceptions, but they're few and far between. And as several have mentioned, unless it's listed somewhere on her profile, she will not be found by her married name in a search.