which sentence or sentences have correct parallel structure? on most saturday and sunday afternoons, you…

which sentence or sentences have correct parallel structure? on most saturday and sunday afternoons, you will find my mother either in her garden or at the library. on most saturday and sunday afternoons, you will find my mother in either her garden or at the library.
Answer
Brief Explanations:
Parallel structure requires balance in grammar. In the first sentence, "in her garden" and "at the library" are prepositional - phrase parallel. In the second, "in either her garden" disrupts the parallelism as the preposition "in" should not come before "either". So only the first sentence has correct parallel structure.
Answer:
On most Saturday and Sunday afternoons, you will find my mother either in her garden or at the library.