I'm so very sorry! I know how saddening it can be. Last year was really tight for us. I was upset because we'd always given a "big" present and there was always a "big" present from Santa. Not last year.
There are programs out there that specifically focus on teens/older kids. Toys For Teens is one of them. Boy Scouts troops across the country look for families to "adopt" or programs to participate in that provide gifts for older kids. My sons are going to Target with Troop money on Saturday to purchase for boys and girls their own ages. Schools and churches, toys for tots, and other service organizations are definitely out there.
I understand all about pride, especially for family members, but pose it a different way....if you found out that your best friend or sister or bother was not going to be able to give anything to their kids for Christmas, wouldn't you want them to ask you for assistance if you could give it? I know I would. In fact, I'd be upset knowing my niece or nephew or close friends went without when I could have helped. And while I never would ask for myself, I would do it in a moment for my family. You indicated that you want to show that you did it for your family, I say, show that you put your family first in asking for help. Show that it's okay to lean on people who love you.
And, no matter what everyone brings, hosting a holiday meal costs. For the food, for the drinks, for the condiments. It all adds up a bit at a time. So you're doing something for everyone else, it's not out of the realm of propriety to ask them for help for what you need/want.
How 'bout something like this.....you ask your Mom or other friend or family member for enough to cover a couple of family games, and put them under the tree for the kids to open and you can play them. My DS's (age 10 & 12) love texas hold'em and it's maybe $10 for the inexpensive set. If you have cards already, you could actually buy poker chips at someplace like
WalMart for about $3.
Do you sew? One of my very favorite gifts when I was around 12 or 13 was a quilt that a family member made me. I just LOVED it and had it forever. There are other things that you can make, even for kids that age, that would be used and cherished. A jewlery holder (the kind you roll up). A travel bag, a tote bag, a wreath, homemade ornaments (my family started me on ornaments when I was 10 with the thought that I would then have a nice collection when I went off to college. Anything personalized is great, too.
Do you have digital pictures? If so, you could make them picture CD's that are their special pictures, with performances, holidays, birthdays, friends, etc. Homemade picture frames with special pictures could be special, too.
They're old enough that you could sit down and have a "brainstorming session" and talk about what you might have in/around your house or that could be very inexpensively purchased, for each other and family members.
Sending you warm hugs during the holiday season.