Actually, if you can keep your client base down, you can work as much (or as little) as you like most of the time bookkeeping. As you know, certain times of the years will be super-busy, but otherwise you should be able to control things. You just have to be able to say No to new business.
I really think going into partnership with someone who has fix-it skills is the way to go -- a guy or gal who can fix small appliances (breadmakers), or computers or cell phones would be ideal. And they are so busy, they need a secretary/bookkeeper to keep track of the office stuff. You'll both win with this combo, I think.
Otherwise . . . hmm. Kitchen garden design? Used clothing consignment shops? Lots of rich people in Houston, who may have good things to sell at your shop. (Lots of overextended people in Houston too, who need to make a quick buck, I bet, selling their unneeded things.)