The two options i have been given is either A) Have a co-signer.

Unfortunately $100,000 does not buy much in San Diego and I do not have a co-signor. 

She could get into an accident running an errand for you and the plaintiff's attorney will be happy to prove she was your employee at the time and you will be a co-defendant, and then the government guys show up with back taxes and fines.etc.Now for paying a percent of each deal.

I do own a co-op in Manhattan.

In this way you are not a lender but a co-owner in title.

As to being in title, the seller is in title, the buyer has an encumbrance and the ownership of that has passed with probate, nothing needs to be done as that will be picked up from a title search and the buyer may sell her interests, hers from being a co-buyer together with those interests inherited.

The day after we contacted the realtor, we got a call from a co-worker of my mother-in-law, saying she is very interested and wants to come look at the house.

Central heat but no central AC o just room heaters and window units? 

I have a co-worker who ended moving back into a rental for two years to restart the clock.

I have 750 credit score but a low 22,000 income so im going to need a co signer for a house in my criteria.