M.J.
There honestly is no such thing as a steady income when you're self-employed. I have been a freelance public relations writer for nine years now and my income has varied a lot each year. That's one of the risks of working from home (unless you're telecommuting, but there aren't many of those jobs).
Keep in mind, too, that if you need to earn a professional income, you will likely need childcare so you have consistent work time.
The site www.wahm.com has some great articles on getting started.
Good luck!