They are asking you for Judgment. You say: "Lord Allah is giving Judgment to you concerning ‘Kalala’; if any person dies having no child but has a sister, then she has half of anything he leaves, while he will inherit it if she has no child. If the deceased has two sisters, they both have two-thirds of whatever he leaves, if there are more brothers or sisters, then the male has the share as two sisters would have, Allah is explaining things for not to go astray, and Allah is the Knower of everything.
See explanation 4: 12. Whoever dies without having a father, mother, or children as inheritors is called Kalalath. Here mentioned inheritors of ‘Kalalath’ is the brother or sister from the same father. They will get a share of heir equal to the children to have from same father as explained in verse 4: 11. If the ‘Kalalath’ has more than two brothers and sisters, then each brother will have the same share as two sisters would have, like for the brothers and sisters from the same father as explained in verse 4: 11. If the deceased ‘Kalalath’ is a man having a wife as the direct heir, then the brother and sister will get the balance after the wife’s share is settled. If the deceased ‘Kalalath’ is a woman having a husband as the direct heir, then the brother and sister will get the balance after the husband’s share is settled. Lord gives all these instructions to mankind not to go astray. But as Satan obstructs mankind from the Straightpath Adhikr, most of the people are not following these instructions from their Lord in their day-to-day life. See explanation 1: 6-7; 4: 13-14, and 167.