Is Zakat to be paid on my two sums of money for a boy and a girl together, or does each sum have its own separate Zakat?

The money must be immediately withdrawn from the usurious savings account, and the usurious interest disposed of by spending it on charitable causes. Zakat (definition) is obligatory only on the principal capital and lawful profits (if it is not usurious), but not on usurious interest. Zakat becomes obligatory if the share of each, the boy and the girl, reaches the nisab (definition) individually, even if they are in one account. However, if the money belongs to the questioner and she is saving it for her children, then Zakat is obligatory on her if it reaches the nisab.