How easy is it for a trailing spouse to get a work visa to teach English?

I have an opportunity to teach English part-time at a foreign company, but they are not able to hire me full or part-time or assist with getting me a work visa. My family and I already live in Shanghai (we moved here for my husband's job and he has the work visa). What are the options for me to get a visa so I can work as a independent consultant teaching English? Setting up my own "business" to do so seems near impossible. Other ideas?