did I blow this?

I am negotiating with a company for compensation. They gave me an offer and I countered with my expectations. yesterday talked with HR about some details for compensation. basically, they can't offer more than what they did and I told her about difficulties on my side. I thnk I am very reasonable and she said she would bring my expectation back to the company to see if they can do sth. They should let me know today. But she said she would do this through email, which made me wonder if it is another round of negotiation, why do it through email? I become nervous now. any thoughts?