I think that the custom of turning surnames such as
Kirk into given names is more widespread in Scotland itself than it would be in
Ireland.
I would bet that people with Scottish ancestry in the USA are more likely to give children names that they think are romantically linked to Scotland than other parents are. I think that
Heather,
Wallace, and
Arran might be names with Scottish connections in this way.
Skye seems to have first been used as a girls' name for a particular fictional character, the title character of the 1957 novel
Skye Cameron by the American author
Phyllis A.
Whitney:
http://www.phyllisawhitney.com/Skye%20Cameron.htm
In the novel the character is said to have been given the name because her father was born on the isle of
Skye, but whether any non-fictional
Skye has received the name because of a similar connection is unknown. :)