I can't help with the adoption details but I do know a little about the two people you mention.

Dr Scharff (b.1858) and Jane (b.1879) had one child Marjorie in 1921 as far as I can tell - which was about a year after they got married.
They met while working together in the Natural History Museum in Dublin (Scharff was the Keeper, Stephens a museum assistant). It was his second marraige. After they married and he retired they moved back to England (where he was from). He died in 1934 but she lived on until 1959. They are both buried, as far as I can surmise, in Durrington Cemetery, Findon Road, Worthing.

I don't know of any connection to Co. Carlow however.

I hope you're search is going well!