I'm glad you're taking the guilt part out!
And I think the idea of sending ONE of them is a nice move as well; I was going to suggest it, even.
But I think you might be able to do something more than "thinking of you."
Maybe say, "When I see them, I remember [insert POSITIVE thing here that's sort of neutral; how much she loves kitties; that she had a shirt with gold threads in it that you were thinking of when you chose the colors for the heart]."
Or maybe something even MORE neutral, perhaps about the objects themselves, the sort of thing you'd say to an acquaintance you were showing them to, like, "The glaze on the heart was sort of tricky--I actually did it twice to get an even coating."
And for the last graph, then maybe something light and short: "Think about you often."
My mom once said to me, "I love you so hard, sweetie." It made me cry. of course, we weren't estranged and I was in need to comfort and reassurance. But it felt intensified and more meaningful than "I love you" but WITHOUT being clingy or gushy the way "I love you so much" could seem.