So, I decided to go for it. Just booked the rooms with Orbitz and called to add my kids. She put me on hold to contact the hotel and came back saying that she couldn't add the kids and that I should cancel my reservation and rebook with 4 people. Well, that's not happening. I know this can be done. Wish me luck with customer service person number 2.
UPDATE: CSR number two did it! Disney must have been busy, because he was on hold with them for around 10-15 minutes (and came back twice to apologize that it was taking so long). However, he came back and said that the kids are added (though, he didn't ask their names, just their ages, so we'll see if I can deal with their names when i link up to MDE....). I do have a Disney confirmation number now, so I'll get on that this afternoon when I'm finished taking down my Christmas decorations
Moral of the story...keep calling until someone can help you. I'm wondering if my first person didn't understand what I wanted, as she didn't ask the names or ages of the kids...though I did tell her I needed to add two children that were under 18. The second time I specifically said I needed to add my girls who were 10 and 12..,..