I searched Ancestry for "Robert Cowie, born in Scotland in 1832 and died in Canada." The return had an 1841 census of Dundee with Robert Cowie,10, Barbara,45, John Cowie 20,,Eliza 10 (must have been a twin of Robert) and George,5
That makes Barbara born in 1796. So the Barbara Cowie who arrived in New York May 28. 1848, age 30 is either a daughter or neice of the older one..She was married to James Cowie.THe ship was the Harmony. James is listed as 34 if that helps you any.Jessie