Given that a contract is probably worth 50k+ to your wife, traditional sales approaches are probably a good fit. Unless she wants to do data-set building, I would assume that her target businesses are sophisticated enough to be keeping data. So start there, make a list of businesses that fit the profile, find contacts (put them in a spreadsheet) and start calling or emailing. No magic, just a grind and a lot of rejection.
In terms of a longer-term strategy, she might pursue some sort of content strategy and start funnelling traffic to her website that way. Some % of that will convert to leads and some % of those will convert to clients. Once you get that pipeline set up, you can spend infinite time optimizing whatever parts of that pipeline. I assume though, that in the short-term, she needs work now and not x months from now. "Traditional sales" are likely a better fit in that case.
She might also consider joining a referral network like BNI if there's a local chapter(s) that look like there are enough members that fit your target profile.
And as the other commenter mentioned, your first port of call should be friends and family. Don't harangue them for a sale, just let them know your shingle is out. Presumably some % of them want you to succeed and you'll probably get a lead or two kicked your way in fairly short order.
