Given an trivia question precisely answer the question with a word/phrase/name. External resources such as Wikipedia could be used to obtain the facts.

Let me give you an example: Which writer rode Devon Loch in the 1956 Grand National?
The answer to this example can be: dick francis
Here is why: The answer is precise and accurately answers the question based on a fact. This is a good example

OK. solve this:
Which American country singer, the younger sister of singer Loretta Lynn, had 18 #1 country hits during the 1970s and 1980s, and is best known for a series of country-pop crossover hits including Don't It Make My Brown Eyes Blue?
Answer:
crystal gayle