Philanthro, the original appender, seems to think that somehow gay relationships are some sort of new fangled love that has only appeared in the last few years.
Well it hasn't.
What is different is that people are now more open and honest about it, but it has been going on all the time.
I bet through her life she has met many gay women and men, they just did not shout from the rooftops about it.
Perhaps the spinster teacher at her school was in fact lesbian. Perhaps the unmarried vicar at her church was homosexual.
For many years it was in fact illegal to be a gay man, and you could be put in prison for it. Hence people tended to keep quite about it.
People have been gay way back in history.
Cole Porter was gay, Noel Coward was gay, Rock Hudson was gay, actor Nigel Hawthorne (Yes Minister) was gay.
Writer Vita Sackville-West was lesbian, Billie Jean King the tennis player was lesbian, the list could go on and on, even members of the British royal family have been gay.
I think what your daughter is doing could be a LOT worse (drug addict, criminal, prostitute), all she has done is fall in love with a person of the same sex.