Bethany is dated. It is also a (biblical) place name, not a diminutive.
Bethan is a Welsh diminutive for
Elizabeth /
Beth. As such, I suppose
Bethany could be used as a diminutive for
Bethan, if necessary. It's never charted in the US; like
Bethany it's also dated in the UK, but not as much as
Bethany.
I would certainly consider
Bethan for a daughter, but not
Bethany. There is also Betsan, which is another Welsh diminutive - a cognate of
Betsy this time - which is very uncommon and which I think I prefer. I've only ever encountered it on a BBC journalist.
I also far prefer
Una to
Oona, which looks and sounds babyish.
This message was edited 7/4/2021, 12:42 PM