Have you noticed her licking the area? It doesn’t look too bad to me. This online info might help:"The most common complication of spay surgeries is minor incision opening. There usually isn’t a need to worry if a small portion of the skin incision opens slightly, because the underlying suture layers probably are intact. Very slightly open incisions usually heal well. However, any time a pet’s incision looks questionable the best bet is to have a veterinarian check the site as soon as possible.” I would just keep an eye on the area for any signs of weeping or discoloration.