Complex sentence: Sylvia is a young girl that disliked the city, so she left the city to live with her grandmother, Mrs. Tilley, in the woods of New England and has become friends with her cow, Miss Moolly.
Split into simpler sentences: Sylvia is a young girl that disliked the city, so she left the city to live with her grandmother, Mrs. Tilley. Sylvia goes in the woods of New England has become friends with her cow, Miss Moolly.