"Alex actually debuted in the PC version of the game last year, but the skin was randomly assigned, so you didn't have a choice whether you played as a boy or girl."
Actually, that's not quite true. She WAS offered randomly at first, during the snapshots, but since 1.8 came out, all you had to do was discover that you could download the girl form on your own page at Minecraft.net, and you could switch. If you log in to your Profile page, you'll see this.

- SteveOrAlex-MinecraftProfile.png (488.83 KiB) Viewed 563 times
I think the guy who wrote that article was actually meaning that the console version of the game was finally going to get Alex, and that she'd come with six skins. He may also have been a bit confused about how Alex is being offered on the PC.
For the PC, she doesn't come with anything but the skin. You can download alternative skins all over the net, just like you can for Steve.
You can see that both are being offered here (and have been for quite some time, now):
http://www.planetminecraft.com/resources/skins/Here's where I learned about switching:
http://minecraft.gamepedia.com/SkinThat one has not yet been updated about the announcement below, and only shows the 8 choices for Steve skins that console players had before today (it's now Wednesday, here).

Here's the official announcement.
https://mojang.com/2015/04/new-skins-ac ... nts-music/Notice this line:
"Players on all consoles will get the Alex skins for free this Wednesday."
Here's the totally official announcement back on September 26, 2014, about Alex:
https://help.mojang.com/customer/portal ... raft-skins