Dave,
I searched for Bernard & Rose’s marriage and for the baptisms of their children in the Irish baptism records on Ancestry but without success. Not every parish has records for that period so probably they came from one of the parishes without records.
Rose Murphy died in Dundee in 1858. Her death certificate gives her parents as Abraham Charleton & Margaret Morgan. I searched for any mention of Abraham Charleton (not the most common name) but without success. Morgan is a fairly common Co Down surname and I was not able to identify a likely Margaret Morgan.
Bernard Murphy looks to have died before death registration began in 1855 in Scotland so I can’t find any information on his parents.
There’s a Rose Charleton in the parish records for Drumgooland parish. Can’t be your Rose obviously as she was Rose Murphy by then but some families repeated names according to a family naming pattern and so it might be a cousin or other relative.
http://freepages.rootsweb.com/~rosdavies/genealogy/SURNAMES/C/CeCi.htm
Seid in the 1851 census will likely be Sadie, a common diminutive for Sarah. (Sally is another variant of that name).