Well where was she hiding it? she's a special yinglet and has a pouch at her stomach which is a vertical slit in which she places things she stole or found, like this wonderfull yinglet artifact that changes people in to yinglets! perfect!
Thank you shardofconfusion for this wonderfull bit, now to make more yinglets my dream of being a matriarch will be fullfilled! (oneday)