I knew a
Julia Dorothy once who pretended to be sorry that
Dorothy wasn't her fn. She said it would have been so quick and easy to sign her name with a full stop.
I like the longevity of
Dottie. It must, surely, go back to the time (pre-18th century, at a guess) when the -th- in
Dorothy was pronounced like a -t-, similar to
Thomas and, outside the US,
Anthony.
As a nn, though, it has its drawbacks. But there really isn't a viable alternative. Except I remember a
Dorothy at school who was called Doth by this one teacher "because she was a little busy bee". Took us years to figure that out.