First thing you need to do is memorize all the protected classes. They start at the Federal level but there can also be State, County and local municipal protected classes.
After that Source of Income is a protected class in many respects. My concern would be proving her sources of income. Does she receive enough income from all sources to meet your established rental criteria.
You need to establish your rental criteria before listing a property for rent. This can vary by type and location of the property. IS this an A+ rental or do you work in a low-income area. Establish a minimum credit score. minimum income, time on job and whatever else you need to consider but have it in writing and apply it the equally and fairly to every applicant who wants your property.
After receiving their application go see where they are currently living. Pigs are pigs and they only thing you can do is change the location of their pig-sty.
Finally, be careful what you put in print. Who knows when an attorney can subpoena your social media accounts.
I am not an attorney and don't play one on television. take care.