I spend money on postcards, distressed lists and a website.

This website is a nice starting point as you are deciding on what location to choose from.

.: I set up LLC's on the secretary of state website for $50 and it takes about 10 minutes. 

I have no experience with this group but just visited their website. 

There's a self-proclaimed Section 8 guru online who claims he hires random property managers through this website called Thumbtack.

At my age, I wonder if it’s too late to "get rich slow," as is the case with most real estate investing.I’m curious: is there a section of this website or a community that focuses on late-start investors?

Website shows up as not protected domain - and no longer in existence that should say enough 

Should know tomorrow if it is accepted. 

You can set it up yourself at www.sunbiz.org , which is the website for the State of FL Division of Corporations.

She's not going to have any leg to stand on in court if you get that far unless there's some explicit language prohibiting the owner from assigning responsibilities to another legally authorized party, and I'm guessing there isn't if another PM company was maintaining the lease and provisions - and the fact that the tenant was voluntarily working with the other PM confirms the acceptance of an authorized agent even if it's not explicitly stated, the same way if you accept rent from a tenant after a lease expires you imply acceptance of the lease terms continuing (which is why you should always have a holdover provision).