Hemophilia Royal Family ( x-linked disease example)

Hemophilia is an X-linked recessive disorder. The blood of a hemophiliac lacks the ability to clot, due to the fact that one or more of the plasma proteins required to form a clot is absent or reduced in their blood.
A recessive gene, it is carried on the female chromosome X . Males possess XY chromosomes and females XX. Since females have two X chromosomes, they are more often than not carriers.

If you look at the Punnett Square you can see the following.
Each child of a carrier will have a 50% chance of inheriting hemophilia. The daughter of a male haemophiliac will always inherit the disease, while a son cannot ever inherit it. A female will only be affected with haemophilia in the rare circumstance that she inherits mutated X chromosomes from both a hemophiliac father and a carrier mother. No case of such double inheritance is known among Queen Victoria's descendants.
Correction:
1:47 I made a mistake. The H in the lower right box should be lower case h and not a capital letter. H