Complex sentence: When Curtiss first saw Genie she found Genie's behavior bizarre and antisocial, and wrote that she looked extremely dirty and unkempt, but thought that Genie somehow still looked very pretty and remembered being immediately drawn to her.
Split into simpler sentences: When Curtiss first saw Genie she found Genie's behavior bizarre and antisocial, and wrote that she looked extremely dirty and unkempt. Despite this, Curtiss thought Genie somehow still looked very pretty and remembered being immediately drawn to her.