What is incumbent upon one who swore not to do something, then did it many times, so many that she cannot count them? And are there specialized organizations that accept money to discharge the expiation on her behalf, especially if she is a girl who cannot feed the needy herself?

If someone swore an oath multiple times and broke the first oath before the second, then according to the majority of scholars, they must offer expiation for each oath they broke. Some scholars are of the opinion that only one expiation is required if all the oaths were broken before any expiation was offered for any of them. The expiation for an oath is feeding ten needy people, or clothing them, or emancipating a slave. If one cannot find any of these, then they must fast for three days. If the number of expiations is unknown, then it is obligatory to err on the side of caution and offer expiation for what one believes most likely absolves their responsibility. It is permissible to give money to trustworthy charitable organizations to undertake the feeding on your behalf.