Looking for a manhwa

i cant rmb the title of this manhwa..i think i read it 3/4 years ago, it starts of with a maid saving her master from eating poison..but bcs she consumed it in his stead, she shrunk and became a kid..and then she was sent to live w another family who are known to be villains, but they end up doting on her. her hair was mint green or blue.. That’s as much as i remembered. I’m not sure how right my memory is but i’m just curious how that manhwa progressed. please lmk if you know what im talking about!