Visa application - FL / NY - help!

My mom is located in FL and I am in NY. We are traveling to Beijing in Sept - we have flights and hotels booked. It is easy for me to get one in NY in person and I had hoped to have my mom mail hers to me to process, but I believe she has to process hers through the Houston consulate since she is in FL.

Is it true you cannot mail in applications? How is someone from Florida suppose to get one processed in Houston?

Does anyone know a trusted company / agent that will process this for a reasonable price?

Helped needed. I've tried to call the Houston office repeatedly with out any answer.
Thanks