"Afternoon in Linen"
from The Lottery and Other Stories, by Shirley Jackson
I can sympathize with Harriet's not wanting to be forced to put herself-- her piano-playing, her poetry, her private, creative self-- on display. Especially when her grandmother is just trying to "show her off" in comparison with a friend's child. Especially with a taunting male peer looking on, clearly plotting to tell everyone at school the humiliating secret that she writes poetry. Some things are so much better kept to yourself, until you decide to share them. (But how humiliating for her grandmother! And I'm sure she didn't mean any harm...)
I wonder if Jackson was drawing on her own experiences (as a child? even as an adult?) of being asked/forced to share private things when she'd rather not. It seems likely.