In a section which highlights Rose's editing instincts, she advises:
I still think that the place to begin is the house on Plum Creek. There are four years to skip if Laura is twelve; she was 8 in Plum Creek when she started school. Therefore the more nearly you can tie the two books together the better, and the house on Plum Creek will do that.
You must take into account the actual distinction between truth and fact. It is beyond all human power to tell all the facts. Your whole lifetime spent at nothing else would not tell all the facts of one morning in your life, just any ordinary morning when you get up, dress, get breakfast and wash the dishes. Facts are infinite in number. The truth is a meaning underlying them; you tell the truth by selecting the facts to illustrate it. All your travels to Burr Oak and back can be skipped because they do not mean anything except elapsed time. Essentially the family is the same except that time has passed. It is not a fact, but it is perfectly true to take them west from the house on Plum Creek, where everything that has happened during this time might as truthfully have occurred as where it did occur.
But then you also have glimpses of fascinating material which Rose didn't feel fit the expectations of readers:
You have a brief scene in which Laura threatens to kill Charley with a knife, but that has to be cut out. A 12-year-old girl whose cousin wants to kiss her does not normally threaten him with a knife; she laughs and kisses him, he's her cousin. Or if she's shy or doesn't like him she just escapes, and the incident is not important enough to mention. Here you have a young girl, just 12 years old, who's led rather an isolated life with father, mother, sisters in the country, and you can not have her suddenly acting like a slum child who has protected her virginity from street gangs since she was seven or eight. Maybe you did, but you can not do it in fiction; you can not make it credible in under ten or twelve thousand words, and if you do make it credible it's not a child's book. I remember when I was five year old or so, and Mrs. Boast let those hoodlums take me home, I ran away from a hulking big brute who tried to kiss me, and his motive was pure sex sadism which I recognized well enough without knowing at all what it was. I suppose something of that kind was in this incident. But it is not child's book stuff. We'll just have to manufacture another kind of cousin, that's all. Seems to me the normal thing would be to have both Louisa and Charley now so much older that they pay little attention to 12-year-olds. Laura just sees them, as she did in the Big Woods.