For Mother's Day last year we made this poem for Grandma (and one for me too). It is simple to do with your kids and basically free.
I typed up a poem and printed in a nice font on a piece of card stock. The kids used tempura paint to make their little handprints, and then signed their names. Make sure you put the year on it so you can see how much their handprints change over the years.
We mounted it on a larger piece of black card stock, or you can frame it. Gramma will love it
I chose this poem because it is one of my favorites, but there are many "handprint poems" if you just do a google search. You can make adjustments according to one child vs multiples.
"Sometimes you get discouraged
Because we are so small,
And always leave our fingerprints
On furniture and walls.
But everyday we're growing,
We'll be all grown up someday.
And all these tiny handprints
Will simply fade away.
So here are our handprints
Just so you can recall,
Exactly how our fingers looked
When we were very small!"
Here is the final product .. so precious: