The answer to the question is no, you can’t expect to find
black sand beaches on Kauai, it is because black sand beaches are only found on
islands that are recently have been formed from the black larva that has been
breakdown from the volcanoes that had been erupted and Kauai is not included.
You can only expect to find at this island is white and yellow sand beaches.
A person can only show a recessive trait if both of their parents carried at least one copy of each of the recessive allele. The parents do not need to show the trait, as one copy is not enough to reveal it, but they must both carry it.
Hope this helped!
Whats the question here?? are you asking which disease she has????