Is Zakat obligatory on 40 grams of gold for each of my three daughters?

Zakat is obligatory on jewelry prepared for use if it reaches the nisab and a full year passes over it. If a father gives his daughters jewelry as a loan, then the jewelry remains his property and he must pay zakat on it if it reaches the nisab. However, if he transfers ownership of it to them, then there is no zakat on it unless the share of each one of them individually reaches the nisab, because the ownership of each one is separate from the other.