As others have said, she needs to go into a sober house. If you pay for her to get her own place, especially in a drug ridden city like New Haven, that is putting her on the express train to relapse. Of course she would prefer a studio or 1br versus going into a sober house, but it’s not on her dime, it’s on yours. I know you don’t want to set her up for failure.

Your best bet is to call somewhere like the APT Foundation and ask them if they have lists of sober houses in the area. Not to mention, rooms in sober houses are more likely to be within her (your) budget range. A quick Google search found this: https://www.womensoberhousing.com/city/ct-new_haven.html

Best of luck to you and your friend. I hope she is very grateful for your kindness.