The first paragraph contains only 2 sentences. She is writing how she speaks, and not the SAE sentence structure. In the second paragraph as well, there is a run on sentence. Again, Berry seems to be writing how she speaks. Maybe this is to give more emotion to the letter: to make it more informal. She even addresses the recipient as "friend." The letter is meant to grasp at the recipients heart and emotions. It is very persuasive in this effect.
Miss Martha Berry, “MB52_20_11_001.jpg.” Martha Berry Digital Archive. Eds. Schlitz, Stephanie A., Penny Andrews, et al. Mount Berry: Berry College, 2011. accessed February 6, 2023, https://mbda.berry.edu/items/show/593.