JMF,
My opinion would be, your daughter has a right to voice her opinions, and you have a right to listen and decide what is in the best interest for YOU.
I see in your post your codependent behavior coming through
, trying your best to smooth things over and attempt to soften the discord.
Take yourself out of the equation.
Also, your daughter may feel that your attention has been mainly focused on your son, due to his addiction, while she, being the "good" child has taken a back seat. I think she made that point clear when she was speaking of her needing money.
Hugs..