I wouldn't get a gift card for the 10 year old two reasons:
1. Too impersonal.
2. Kids want it now, as opposed to the near future.
I would buy her a bracelet making kit ,as my grandaughter, (she is also 10 years old), seems to like that a lot. They are fairly inexpensive and can be obtained on
Amazon.com: Online Shopping for Electronics, Apparel, Computers, Books, DVDs & more.
For people who have everything, I think , something personal, like a picture with a collage of the years they were growing up as well as other family members. Maybe, they could bond on earlier memories when they were close, as opposed to bringing up their differences.
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"It doesn't cost "nuttin", to be nice". 
MOM
I just want to do the right thing! Uncle Joe, (my hero).