Ann is so concrete, she can't understand why anyone would do something they don't want to. She doesn't seem to feel vulnerable, so doesn't understand people who do or who succumb to pressure unless she can see why. A failure of imagination I think, rather than an intrinsic nastiness.
And she tends to vote to promote an old fashioned view of marriage and family life. It's a bit logical, if you think about it. Marriage is (and has been for hundreds of years) between a man and a woman, for the purpose of the family unit. Gay people simply don't fit that pattern. For her it's a definitional thing.
She does see homosexuality as 'less than' heterosexuality. But that was the norm until relatively recently.
I stress, I don't agree with her, wouldn't vote with her, but I don't think having those opinions makes her unusual or vile. She'd feed and clothe her single parent lesbian neighbour, should she need it, without a word I'm sure. Many people with 'right on' views would behave far worse.