Complex sentence: Jane's character is contrasted with Elizabeth's as sweeter, shyer, and equally sensible, but not as clever (but she is aware of this fact); her most notable trait is a desire to see only the good in others.
Split into simpler sentences: Jane's character is contrasted with Elizabeth's as sweeter, shyer, and equally sensible, but not quite as clever. Her most notable trait is a desire to see only the good in others.