Well, I did internships in my 50’s. All through my 40’s and 50’s I did volunteer community service, and when my kids were older I did internships in the area of my interest. My resume looks good, considering (relatively speaking). When I did apply for work, I got interviews almost every time I applied to positions on craigslist, anyway.
I have watched all three of my kids gain skills, build resumes, and make connections through internships. I tell my own daughter that they may be more important than her degree. Employers want people who have the skills for the job. In the case of someone who wants to do something specific, like bookkeeping, of course coursework is important though.
Thirty-five is young, and so far your experience is in a field you don’t want to work in. I would try to build a resume of sorts.
I really sincerely wish you good luck. Your situation is a hard one and I admire your commitment.