First off you need to stop the emailing, first thing tomorrow you need to go over to her property and talk with her. Bring the printed out emails and make sure that all of the dates and times are visible on the emails.
During your conversation, STAY CALM! Otherwise you shouldn't even bother going over because she will just look for any reason to get mad at you and kick you off her property. Let her know which days you were personally there, and which days your crew was there without you. Have all of this typed up and printed out so it is as plain as day for her to see it. Along with the specifics of any work that was done during each visit.
If she doesn't pay after the conversation, and refuses to pay you politely pull out a piece of paper that gives her 5, 7, or 10 days before you file a law suit against her in court. Make sure all of this looks 100% legitimate. As well stating that she will have to also pay for any of your legal fees should she not pay for the services rendered.
"Services Rendered" is a good word to use, it sounds official, seriously.
There is an Old Blue Chair for each and every one of us, we just have to find it.
2006 GMC Sierra 2500hd crew cab
BOSS 8'2" Power V
Hustler X-one 60"
Toro Proline 36" wb w/t-bar controls
JS46 22" walk-behind (wouldn't recommend)
Shindaiwa T254, Echo trimmers, chainsaws, pole hedge trimmer, pole saw, hedge trimmer
Shindaiwa 633 and Husqvarna 130BT blower