Newsflash: Buyer owes agent commission?

My wife and I made an offer on a house. The house was sent to us by our agent, but we saw it at an open house. Made a full asking price offer.My agent called me later to let me know the seller is only offering 1.5% commission to buyers agent and that her realty co won’t accept less than 2.5%, meaning I am on the hook for 1%. I did not know this prior to the offer. She told me not to sign the broker svc agreement as part of the offer and that we would negotiate the price later or possibly with the seller or “find it in the inspection”. The last one sounds shady af to me but I’m a neophyte in real estate. Here’s my dilemma. If I get stuck with 1%, can I simply back out and find a realtor who will take less (I think 0.5% or flat $3k more appropriate) but still keep my offer in place? Am I tied to my realtor regarding this house since an offer has already been made? I like the realtor but she sprung this on us last minute as the offer was being made, not before. She also sent us a low commission house, so she would have already known her commission was going to be lower. Any expedient advice is appreciated as this all going down today. EDIT: thank you to everyone who took time to respond. We called and talked to her, made some really great points and My agent was actually very understanding and agreed to 1.5%. Thanks everyone! Double edit: our offer was accepted!