Unless you are symptomatic I dont see a need in testing for actual CF. Some carriers are symptomatic BTW, but that doesnt mean they have CF itself.
Knowing which gene you have could be beneficial for the families. IF someone else in either side of the family had someone that needed to be tested, you would know at least one gene to test for. Its not a guarantee, but its a starting point.
As far as your chilod & which parent gave her which gene....it doesnt make a difference in her clinical outcome. As I said its more of a family might want to know type thing. This is especially true for the families that like to cast blame....she didnt get it from MY side type thing.....
Good Luck