Sherry, not going to get into the selling the ticket thing, but as far as giving away, I would like to point out this quote from Disney's official ticket buying FAQ:
"Can I order and pay for the Disney's eTickets on my credit card and give them to another guest as a gift?
Yes. However, your tickets become active as soon as you purchase them. The
Disneyland Resort is not responsible for lost or stolen tickets so please treat them like you would treat any other ticket."
The key to the non-transferability of Disney tickets is whether they have been used or not. You can certainly buy a ticket and give it away to whoever you want as a gift so long as it has not been used for entry prior to being given away.
To the poster who wanted to know about what to do with a leftover ticket, occasionally Disney will sprinkle a little pixie dust and help out with a situation like this. If you get to the point of knowing that your daughter will not be able to go, contact Disney immediately and see if they would be willing to issue a refund. The tickets are officially non-returnable, and most people have found that Disney holds the line on this. There are occasional exceptions though, so if you haven't come up with any other solution, it never hurts to ask.