What is the Shar'i ruling on the the division of the aforementioned land, and is the division that took place considered legitimate in Sharia, and what is the sister's share of the house?

It is permissible for a father to divide his wealth among his children as a gift during his lifetime, while he is in good health and sound mind. Each of them then becomes the owner of what is in their possession, with no one else sharing in it. However, if the division is without legal transfer of ownership, it is void, and all children inherit what the father owns, with the male receiving the share of two females.

As for the dispute between the questioner and her sister regarding the property, reconciliation is advised, and resorting to discord should be avoided. The questioner should have allowed her sister to build above her house, fulfilling her promise, to resolve the conflict and foster affection. The sister has the right to share in the building by paying half of its value, and she has the right to half of the land rent for the past period, unless she remained silent, consenting to it.