Craigslist Etiquette

I recently sold National Treasure, Fight Club, and Step Up on Craigslist. The first two were purchased by a man named Alex who sent his wife to pick them up at my house. I ran down the stairs barefoot to meet her in my driveway; she had a sleeping baby in the car and didn't want to leave him. Smooth exchange.

Step Up was purchased by Jamie. We emailed back and forth a few times to nail down a time and place to exchange the movie for the moolah. She seemed really excited for her two daughters to finally have a copy of their own. We planned to meet in the Wendy's parking lot at 5:15pm on Friday. Jamie was hard to find, though. She could be any of these women. Luckily I had Jamie's number and made the call. A man answered,
"Hello?"
"Hey! This is Emilie with Step Up. I'm calling for Jamie."
"This is Jamie."
"Oh... Oh! Ah...I'm at Wendy's. Are you here yet?"
"Yeah. I'm right in front of you." I looked a few feet in front of me and saw a man with a cell phone to his ear looking right at me.
"Yeeaah..."
Not so smooth.

So I'm left to wonder what the proper etiquette might be in a situation where you are to meet someone who's name is ambiguous regarding gender. "So... are you a man or a woman?" It just doesn't seem appropriate, you know? You'd think that they (meaning those with transgender names) would know to tell you what kind of human being to look for in these exchanges. Or they could at least pull an Alex and say, "I'll send my wife."