Is Zakat obligatory for a woman who owns a residential apartment, two apartments designated for rent, a plot of land, in addition to an amount paid as a down payment for the purchase of two villas?

Zakat (definition) is not obligatory on the apartment your friend lives in. As for the two apartments prepared for rent, Zakat is obligatory on their rental income if a year has passed over it and it reaches the nisab (definition) of 85 grams of gold, and the amount of Zakat is one-quarter of one-tenth (2.5%). As for the plot of land, if it is for personal use, there is no Zakat on it. If it is for trade, it should be valued and Zakat paid on it after one year has passed since its purchase price, or Zakat is paid for one year after its sale if it was bought for speculation. The amount paid as part of the price for the two villas is not subject to Zakat because it has transferred to the seller's ownership.