If you was in my shoes. 

I hope to be in your shoes in 10 years.

In your shoes, I would ask several questions.

@Peter Padalino - couple suggestions, as I've been in your shoes.  1) Go crazy on energy efficient items - all LED bulbs, NEST or EcoBee thermostat, etc, etc.  2) Get someone to quote solar power for the roof if you have APS - I went solar and LOVE IT for rentals. 

They pay the mortgage and my utilities (essentially living and owning a home for free - in your shoes you would be cash flowing).Then, depending on what you are doing for a job (or college), it'd be good to establish yourself at work and save enough for your rainy day account (savings in case you lose your job) and then start saving more for a rental property.

I would suggest going that route if I were in your shoes.

@Tom Smith If I were in your shoes, I might rent for 6 months and figure out what I wanted out of my living situation as well as where I'm likely to get the best value.

Ideally, the solution will also be something economical    What would you do if you were in my shoes?   

How'd you resolve this and get business back to usual, and what would you recommend someone in my shoes should be looking at as a best course of action?

If I were in your shoes, I'd probably have a frank and friendly with the tenant and talk a big, threat free game, but point out that her lease does not allow for animals and that she did not disclose the animal to you.