Possible tenant on Social Security and cosigner.... worth it?

[Clare Cui]

I have a 2 bed 1 bath garden unit, I have this possible tenant who is interested, she makes about $3500 with disability and social services. She has a co-signer willing to sign, but I'm hesitant with her age/safety (the garden unit has a steep staircase) and with rent being $1800 is that doable for her? I'm thinking that at least social security is steady, but I don't want to take any risks. Any advice? I have a tender heart but this is also my BUSINESS. Thank you in advance