In my country your kuniah should depend on this form om/abu your first son name , in the case that you don't have son then you can have kunyah related to your elder daughter till you beget a son , then your kuniah would be changed into your son name For example , if you have daughter called "aisha" your kuniah would be Om aisha , If you beget another daughter "Noor" your Kuniah still the same , if you beget a son "Omar" Then your Kuniah is Om omar .............. F you haven't have any child yet ......then you can choose any kuniah that you like.

Yes we can , and its good

We use name of the eldest child. So, if the daughter is elder than the son, her name can be used.

Of course we can!

Of course it isn't a "must" for a teknonym to be derived from the son's name. It ought to be derived from the name of the oldest child. However, you will find parents calling themselves "mother/father of Rana," but the moment they conceive a boy, they decide to be "mother/father of Ziyad." Sometimes parents decide to stick to the oldest daughter's name even after conceiving a boy, but friends and family insist on giving them teknonyms after the son's name. There are even parents who have only daughters and no sons, yet they invent a name of an "imaginary" son and use it. If anything, it shows the amount of unjustifiable misogyny existing in Arab societies. I think teknonyms should be abolished as they deprive a person of their own identity. Your name is the first thing that defines you. Call it a personal prejudice of mine. But I digress again. Feel free to have a kunya derived from your (future) daughter's name regardless.