I like
Robin very much for a boy, certainly enough to use. For a girl I'd expect
Robyn, but I don't like it much. I've got a cousin named
Arthur Robin and always known as
Robin - big, tough petrolhead who used to be a champion rally driver. often with a blind navigator.
Morgan is a family name from way back at the beginning of the 19th century! Judging from the ln, and the address, he had Welsh parents. I wouldn't ever expect to see a female
Morgan, though I believe there are some. I'd use it all right.