We were friends with a male/female couple who married and had children. Then he suddenly announced that he was undergoing gender realignment (it was 'sudden' to us because we do not live very close together and did not see the often. Clearly, this was not 'sudden' to them).
The children called the male persona 'daddy' but the female persona was always, and still is, called by her first name. Unfortunately, although the wife was very supportive and they remain friends, the marriage did not survive and the 'changee' moved to another area.
We still see the wife about once a year but haven't seen the ex since she moved away. I do remember discussing heels and make-up with her once though, which seemed a bit bizzare at the time. She encouraged us to ask any questions we wanted because she felt that we were not being judgemental. She still fancies women - her gender has changed, not her sexual orientation.
The children seemed to accept things well at first, but they have had some counselling since. They still see each other regularly though and she plays an important part in the children's lives (even though they are not 'children' anymore), it's just that she is not 'Daddy' now.
From my point of view, this person was the same inside, however the body was presented. If we believed that 'he' was a nice guy, it stood to reason that 'she' would be a nice woman too.