While parents need not give every one of their children a gift similar to that of the first one to get married, at the time of that marriage, they should be clear in their minds that they will do the same toward their other children when they marry. As for inheritance, this becomes due when a person dies. Every one has heirs, according to his own situation and those of his immediate relatives who survive him. First degree heirs are the deceased's parents, children and spouse. Others may also be entitled to certain shares, according to particular circumstances.
Heirs inherit by right.
Their shares are apportioned by Allah. Perhaps it is useful to remember at this point that, from the Islamic point of view, we do not own our money or property. That charge reverts to Allah on our death. He distributes it to our heirs the way He likes. He has only allowed us discretion to leave by will an amount of our property not exceeding one third of its total.