Just start here and follow the links.
And, no, this isn't an "outing." She's out. If people post their personal information on public websites, then that information is "public."
...in a just and correct world this would not be "news," at least not of the "shocking" type, but we don't live in a just and correct world. We live in a world where the political party in power tries to maintain that power in part by trying to maintain 2nd class status (legal, economic, and social) for a substantial chunk of our population for no other reason than who they have romantic feelings for. We live in a world where the Republican candidate for Senate from Illinois calls the daughter of the Vice President a "selfish hedonist" simply because of who she has decided to make her life partner. We live in a world where a steady stream of homophobic rhetoric is commonplace and accepted as normal, not just from AM hate radio hosts, but from people who are in the highest levels of government.
In a just world this would be "news" in the same way that personal profiles of public figures which regularly include information about their families are "news" -- in the same way that "Chelsea Clinton has a new boyfriend" was always news. But, right now we're in a world where an anti-gay moralizing family vales politician no problems calling other people's kids "selfish hedonists" simply because they're gay. I think it's fair to ask what kind of world Alan Keyes, who wants to be one of 100 senators, wants to create for his daughter.