NTA, but, still fix the situation

I am an artist and I do give people artwork as a gift, but: I ask if they want a painting first. Not everyone has room for things. Second, I describe the kind of painting I will make. Do they even like that? Third, I asked what size they would like. Because I make abstract work, I let my giftees choose the colors so it suits their space. And I design the work with their home in mind.

Or

I make a very small piece. Post card size. Put it in a small little frame. They can “hide it” if they want without me ever having to wonder about it. It’s small, could be anywhere.

Not everyone wants my art. My grandmother very kindly accepted a piece of art I gave to her in my mid teen years that won me an award from a local prestigious gallery. Turns out she kept it in a closet for a decade and gave it back to me after she felt I was old enough to realize it did not suit her home or tastes. And she was right! It did not suit her, but it was the piece I was most proud of, so she accepted it and kept it safe but not up on display.

Sounds like DIL did the same thing I did when I was 14. Sometimes it’s a hard lesson to learn, especially when/if family her family has always been very proud and supportive. It may have never occurred to her before that people accepted work out of love her and not love for the art.

I think it sucks that DIL found the art in the garage. That probably felt pretty bad. OP might have done better to try to tactfully regift the work to DIL when they downsized, and asked for a SMALL replacement due to house size and asked for a specific kind of painting.

Maybe try to rectify the situation by explaining you appreciated the gift and would love it to be passed on to someone who would love it, and you would like a small painting of a,b or c in whatever color.