An 11 year old girl made a neder that if she finds something she was missing she’ll give 20 agarot to tzedeka every week (seemingly for the rest of her life)
She found the object, is the neder chal?
Because she is at an age of “mufla ha-samuch le-ish,” there is room for concern.
However, it is improbable that she really meant she’ll give 20 agurot weekly for the rest of her life, and there is room to doubt this.
Because of this doubt, there is some room to rely on the Kol Nidrei declaration, if she made it on Yom Kippur.
Yet, it is best to do hatarah: Going before three men, mentioning a petach (she can say that she didn’t appreciate the implication of having to give for the rest of her life), and the three of them saying “mutar lach.”