I am looking for some words of wisdom.  The way my 21 year old step daughter treats her dad totally gets under my skin and I don't know how to not let it!  

She is passive aggresive, whiney, and expects dad to save her from every little problem... which he does, so I don't blame her for that one... but I still find it so annoying!  Thankfully she doesn't live with us anymore, but is still "around" a fair bit.  When asked to do even the littlest thing (like put her stuff in our storage space below the house), she either whines and complains or does a crappy job... or both!