Rent to Low income/credit + collection with good cosigner?

[Suduk N.]

My garden unit has been on the market for 2,3 months with only 2 applications so far. The demand has been tepid during this time according to my PM. I have a single mom with 2 kids applicant whose income is barely 2x rent but can provide a good credit score with good income although they are friends not family. She also has low credit score of 500 and a collection for medical bill. 

How is everyone doing in Chicago market during this time? I normally would reject this type of applicant because they don't meet my criteria but the market has not been so good and winter is coming so I may sit on an empty unit for months. What would you guys do in this case?