Gifts to send to a coworker that you never met?

With the company I work with I am always communicating with corporate office (always the same person for me).

She constantly sends me leads, helps me when I make mistakes, and without her help and answering all of my questions I would not have just hit the first major milestone in the company.

I want her to know I appreciate all the work she has done and help she has given. I sent her a card once before when I first started and she sent me my first lead. So what is a good gift I could send this time?