Some will find Little Lord Fauntleroy overly sentimental, especially in our modern, cynical world. In fact, the book itself refers several times to its "romantic story" and the story does have a rather fairy tale neatness to the way everything ties together and makes happy endings.
That said, I still give Little Lord Fauntleroy an enthusiastic recommendation. That the mother and child are idealized, I concur, but we like having an ideal to which to aspire. Not preachy or moralistic, like some similar books, Little Lord Fauntleroy is a satisfying read in which a young boy's love and goodness transforms a self-indulgent and sour old man. An excellent theme, made memorable by a charming story.