You certainly have my attention regarding Florence Nightingale Seddon.
I have come to this line of the Seddon family from two generations back after tracing out my gggg grandfather's second wife's family. Ann Jane Seddon married James Reid on 9 Feb 1835 in Liverpool, England. James Reid was to bring to Australia the authorization to establish the first G.U.O.O.F society in Australia about 1848 in Sydney. Ann Jane was the sister of Richard Seddon who also sailed to Australia. Richard and his wife Eliza arrived almost 2 years early than James and Ann Jane Reid and may have prompted them to also came out to Australia.
My email address is firstname.lastname@example.org and I am very happy to exchange information with you.