The only listing agreement in NJ that would enable you to sell on your own, with no commission liability is an Open Listing Agreement.
I do not practice in New Jersey, so this suggestion might not work...but it should
When you list your home for sale you can name people with whom you already have a relationship..your niece for instance. The stipulation is that if she buys it, then she is excluded from the listing agreement requirements.
You should know that even if you sell "directly" you are still legally required to fulfill all state and local requirements and paperwork. I would be suggest negotiating an arrangement so you have your Realtor handle the transaction and protect you from liability.
Basically you are throwing yourself on the mercy of the court. Legally you are stuck for the commission. However, many agencies might cut you a break and let you pay a sharply reduced fee. It comes down to letting go of the short term monetary gain for the future goodwill. If you were my client, I'd let you off the hook and just let you pay a fee for my time and expense, maybe $1,000-$2,000 depending upon how long you were on the market.
However, there are some barracudas in the industry who might not be so pliable. Hopefully you have not signed on with one of those.
depending upon you relationship with the agent and the office, you are bound by the contract to sell the house through the Realtor. You can also contact the Broker and explain the situation and maybe they will cut the commission and still act on your behalf.
I am sure you can work it out.
What you could do is tell your agent that you have a prospective buyer. And ask if they would reduce their commission if you gave them a referral. Most reasonable agent will agree.
According to my CBSchmidt listing agreements, the answer is no. Unless of course she was listed as an exclusion.
I'd recommend looking over the documents you signed to have your home listed.
Hope that helps!