I think that it would be perfectly natural for grandparents to use "our girl" as a term of endearment for a granddaughter, especially since the Admiral knew Samantha so well and for so long (not to mention that she saved his life on the island). I always thought that she lived with Uncle Gard because his life had become settled since marrying Aunt Cornelia and they were closer to an appropriate age (and temprament) to be parents than Grandmary. I also thought that since they had been married for a while and there were no babies on the way that, although the book obviously never mentioned it, they might have had infertility problems-birth controll was non existent in those days so pregnancy was pretty much unavoidable. I always thought that it was nice that they were able to find exactly what each of them had been missing and create a wonderful family. (ok, I know, they're kids books and I'm reading WAY too much in them. Am I the only one that thought that in the first book of Addy's, that the visiting plantation owner who said how pretty Addy was and that maybe he would buy her to be his indoor servant, had perverted motives?)