Honestly getting hired is not the issue you'll face. If you have the credentials, most shops would love to hire a female technician. It's just good PR. Plus, if they don't hire you and hire a less qualified man, you'd be able to hang them in a discrimination lawsuit. Might sound cynical and a bit asshole-ish but it's just how it is.
The real hurdle you'll face is being accepted by people at the job, both employee and customer alike. The other techs would likely be the first to come around. Most are more concerned with your knowledge base and ability rather than your gender. Some service writers might cause you a hassle but again, most warm up after they know you know what you're doing. Sadly, you will deal with many male customers who will assume that they have more automotive knowledge than you simply because they are men. You'll deal with assholes no matter where you work or what you do, so in the end it comes down to the real question: Is it what you want to do for a living? If so, go for it and the world be damned. If not, keep looking. Hope that helps.