My stepdaughter is treating my husband awful, not sure if I should step in or let him deal with it.?

I have a stepdaughter. She just turned 18, she lives with her mom, we rarely see her. I chat with her when she is over to visit but I wouldn't call our relationship close. The problem I have is that she acts extremely self-deserving (I know her mom hasn't helped this) and very disrespectful to my husband. I'm shocked when I see some of the e-mails she sends him. We basically never see her unless she wants money. I'm all for helping out kids but the way she is acting I personally wouldn't be giving her anything. One way or another she always ends up talking my husband into giving her stuff. Like last week he paid for her letterman's jacket then the next week she is trying to make him feel lousy for not helping her pay for a fancy car. I'm like hello a huge child support check goes to your mother every month plus all the extra stuff you come to us for. I can't believe she would treat someone this way. Anyway to make this short I'm sorta feeling like maybe I should say something to her. I'm looking for advice whether I should just let him deal with it (which he isn't) and let it go or call her out on it.