Boston is a tough (premium) market

So if she does ask for it and decides to not accept the offer until I can prove that I have the funds, how do I get one from a cash buyer without giving them the address of the property or them wanting to know the address of the property?

Traditional financing is going to be tough as a self-employed individual.

Tough to find. 

At the end of the day singe families are tough in NJ for buy and hold but multi families have huge potential if done right.

I’m currently looking for a 3 family in Bushwick / Bed-stuy areas. 4 families are proving impossible within the FHA limits (which really need to be raised for those areas!). 

But because of limits on Zelle payments, he was only able to Zelle me half on Aug 31, and the other half on Sep 1, at 12:10am to prove to me that he's not BSing me and giving me part payments which I refused in the past.

You're going to have to prove that your units comply with the current code.

@Brendan Miller perhaps I will mail another lease, this time as certified mail to prove she got it, can include when I plan to come by, and include documentation that if she doesn't respond then she is out 10/01 and I am finding another tenant.

You might want to get your regulars agent to take a look at it for your market.I'm sure agents fight to keep the deals together if things start to go south, like a tough inspection, or some other issue when the commission is more.