Can we really be sued for breach of contract for this?

Can a realtor sue a seller for breach of contract b/c township can't come out until after the realtor's scheduled closing date? We signed a contract with realtor to sell our 1950's house AS IS in NJ in January. She told us then not need to get c.o. yet. In April, realtor said she has a buyer. She became the buyer's realtor as well--dual agent. We signed the contract the next day after the buyer. When signing, we learned realtor set the closing date for the 3rd week of May and put that in the contract. She said the next step is flood maps for buyer's mortgage, then she hired an inspector for the buyer, who went through our house with realtor and buyer. The realtor nagged us to do more repairs. We got permit for a water filter after NJ water lab test for low ph. May 1, realtor said to get c.o. After installing filter and finishing repairs May 15th, we made c.o. appt with Twp and learned that no appt is available until June. Realtor is angry, threatening to sue for breach of contract.