I'm going to offer a dissenting opinion.
First of all, I don't give gifts because of who the recipient is, but rather because of who I am. If folks don't send thank you notes, it doesn't bother me a bit. Nobody receives $50 without feeling good about it, which would be thanks enough for me because, after all, that's why I'd be sending it.
When my time in this life is done I want my grandkids to think of me fondly - to know that I always remembered them, even at times in their lives when they forgot to remember me. I want them to know that love and generosity aren't always conditional. Just as there were some folks in my earlier years who I didn't properly acknowledge at the time that they offered kindnesses to me, I know my grands aren't always going to "properly" appreciate me.
Here's a thought... If you haven't seen your grands in six years - since they were in their teens - isn't it time you made some arrangements for your mom and hauled yourself to Ohio for a visit? (If you wound up in the hospital for an injury or illness you'd have to make arrangements for her, so it's not impossible to do so.) Be more to them than a check every Christmas and perhaps they'll be more to you than an endorsement on the back of a check.
What I read between the lines of your posts is love, hurt and anger. My family has had a saying for a long time. 90% of life is just showing up. If you want to resolve that unfulfilled love, put a balm on the hurt, and soothe the anger, get thee to Ohio and show your grandkids that they're worth more of an effort to you than a $50 check at Christmas. Re-engage and meet them where they are. Text them, email them, whatever.
p.s. This isn't intended to be harsh or judgmental. I'm just trying to point out that your grands likely see this from an entirely different perspective. You have time to fix it. Ultimately, unless I miss my guess, what you want is a relationship with these kids.
