Both references to Tolkien come from letters written to Jeanne Beatty in February 1960. In the first, Jackson notes that a old family friend "reminds me of the Tolkien RING trilogy; do you know that? or THE HOBBIT? I can't get the kids to read THE HOBBIT although i [sic] love it" (p. 421). The second letter is the more interesting (if perplexing). The relevant portion reads (with Jackson's shunning of capitalization):
i was going to say some awfully profound things about the hobbit because of course that is (i think) the essential of all fantasy; clearly it was not written to satisfy the reader but began years ago when the author lay in bed at night telling himself stories to make up for the spanking or for the fact that other kids wouldn't let him play second base; the non-important things are the ones not important to the author's ego. (why do any of us write, come to that?) i think more of islandia, which is revolting in a sense, full of adolescent prurience (for two hundred pages his hero--a harvard graduate, no less--tries to bring himself in a pitch of boldness so he can put his arm around the heroine, but of course once that first deadly step is taken things move on apace, but still very much of the sixth grade) and yet the book stands as the work of a grown man, and i think that the queen of the elves is exactly what leapt to tolkien's mind when he thought of women; of course, english dons are easily distinguished from errol flynns, and i daresay tolkien's whole knowledge of women might have been early concretized by terror of his headmaster's wife, in any case it is only one step removed from boy's life and you know what they thought of girls there. funny, you don't notice the lack of girls in robinson crusoe; i wonder if that isn't because dafoe never felt called upon to explain that he simply couldn't care less. i am not very coherent; what i am trying to say is that the idea of women as a particularly irritating mystery is very close to tolkien and the islandia man and consequently they get very stiff and sophomoric about the reverence due to queens and princesses and you only know they are not actually the captain of the cricket team of the president of the senior class by the fact that they are insistently referred to as she. i cannot read the second volume of the ring anymore because i think it falls apart, as though as a child he had gone over and over lovingly the fellowship and the good comrades who set out with him ("i will take the ring, although i do not know the way.") on his grail-journey and then found himself, grown-up, without the boy fancy which would continue the story, and had to fall back upon learning and logic to complete it. (surely when he was a boy the book ended with him becoming king of all the countries and on very good terms with his adored mother, the queen of the elves.)
Well, where does one start with this farrago? Jackson clearly knew nothing of Tolkien (or of Austin Tappan Wright, the author of Islandia), and I think her ravings tell us more about what she believed and expected fiction to be about, rather than revealing anything (other than nonsense) about her subjects. Jackson was clearly not much of a literary critic. And sadly her letters aren't very circumspective about her own works--they focus too much on her domestic life. This may please fans of her family chronicles such as Life Among the Savages (1953) and Raising Demons (1957), but it will disappoint admirers of her weird fiction.