Alternate Explanation

The puzzle regarding the relationship of Agnes "Nan" Ross to other passengers on the voyage in 1926 seems to have been resolved. Thanks to James (Ross) who suggested that, rather than being the niece of someone else onboard, the relationship indicated that she was the niece of her contact in Canada (George Blades) and that the presence of the Millers on the same trip was merely co-incidental. Ah well, that one will go on the back burner for now. We still have lots of other puzzles/brick walls to deal with.