As for any spelling mistakes or other errors in her emails, Jaycee has nothing to be ashamed of. The more I hear about this young lady, the more impressed I am by her. She is obviously someone who did miracles with the limited education she had, and she has the drive and interest to learn. If her emails weren't exactly business-like or had lower-case "i's" rather than capitals, that is something easily corrected. She simply didn't know any better, and nobody was teaching her but herself. If the small I's can be interpreted psychologically, I leave up to others.
They don't mean anything other than that she wasn't an expert typer and probably typed the message quickly.
She read books, she certainly would have known about capitalization.