Question

If the majority of females in a pedigree show a trait, does that mean the allele is Y-liked?

Answer 1

No, since females don't even HAVE a Y chromosome. For a trait to appear in a female, it would most likely have to appear on both X chromosomes.

Answer 2

Not necessarily, it could be dominant. So it would only have to be on one X. But than it would also appear in males, because the Y is void.

Answer 3

It is definitely NOT Y-linked. Females don't have a Y chromosome. It could be X-linked dominant, as Krautsourcing said above. Or it could be an autosomal trait (not on the X or Y chromosome), and just based on random chance, more females got the trait than males.