Hi! and Welcome! Tell your DIL that I am really proud of her. I've done three of those and they aren't easy!
As for the ticket price, it really depends on how populated your area is and how many friends and acquaintances you have that have 10 to 15 dollars to spare for a really great cause. If you sold a limited number of tickets, say 150, at $15 each, she would have her entire monies raised.
Please keep us posted on your progress...and send me a PM when the quilt is done. I'll by a ticket.