Parents putting pressure on sister

My sister is starting college application season but she wants to go to a trade school instead. I'm in my junior year of college now. We've kind of lost touch over the years but I still speak to my parents a lot. They've been complaining about her choices to me now, and I want to help her some way. When I was applying they really wanted me to become a doctor but I didn't. Now they want her to become a lawyer. Their families were both poor and they worked hard to go to Ivy League schools and have high paying jobs now. They don't want her going 'down a step' and risking her future, as they think everyone should have office jobs. I don't want her to be poor, but I also don't want her to drop out of a course she hates and can't do academically.

When they were pressuring me into med school it affected me really badly and I still have issues around that. I don't want that for her. What should I do?