Is Zakat obligatory on an orphan's money deposited in an Islamic bank if these funds originated from charities and Zakat?

The majority of scholars hold that zakat is obligatory on the orphan's wealth, even if the money was a charity, and the guardian is responsible for paying it. Zakat is calculated for each charity or zakat received by the orphan with its own new hawl (one lunar year), so zakat becomes due if its hawl passes and it reaches the nisab (minimum threshold) by itself or by being combined with other wealth owned by the orphan. The nisab for banknotes is the equivalent of 85 grams of pure gold or 595 grams of pure silver, and the obligatory amount to be given is one-quarter of one-tenth (2.5%). It is not permissible to give zakat to an orphan if they are not poor.