Cat ate plastic craft letters, should I be concerned?

I believe my cat ate two craft letters. They are small, about one centimeter in length and one centimeter in width. It is hard plastic, definitely not something she could chew. I put a picture on imgur, hopefully it works.

https://imgur.com/a/1rlXKQG

Female
Long haired house cat
9 pounds

She is acting fine. No pain when I press on her stomach. Appetite normal. This happened someone when I left work this morning. She has not had a bowel movement.

Assuming I need to just let it pass, but my worried mother mind is well… worried. Please advise. Thank you!!