Explanation:

The idiom , the best of both the world means, a situation where a person can enjoy two or more completely different things at the same time without losing anything.In the given sentence, the girsl has both a good family and a good job so the idiom best of both the worlds is used to describe that she is lucky because she is not sacrificing on anything to get a particular thing.She has a good job which is her professional life and also a good family which is her personal life and she is having a good time. Hence option 1 is the correct answer.