It’s a very difficult situation that several members have also faced. My only suggestion is to tell her about this terrific site (or sites) you’ve found on line where you’re learning a lot about how to care for your bunnies. Just sound upbeat and fun about it. If she opens up the conversation with you from that point, you can both give her the site name so she can check it out at her leisure (sometimes it’s less embarrassing to learn about this stuff quietly on your own than being lectured) or you can answer her with any tips you’ve learned that she’s asked about.
For example, you could say that you never knew something as simple as going to pet your bunny with your fingers spread out and reaching down from above looks like a claw to a bunny and it scares them because that’s how a bird of prey would swoop down on them. They get more relaxed if they are sheltered where they can’t be attacked, and if you need to catch her again, go after her first with palms up, fingers closed. It may let her know that bunnies are scared out in the open.
But do be careful about lecturing. I know it’s hard. I worked with a woman (I never liked her anyway) who loved having bunnies in common with me. Until I learned that she kept hers, several of them, together in an outdoor hutch. And when that inevitible litter came, she “set them free to experience life as a real bunny”. Thus having a domestic neighborhood overrun with 7 baby bunnies that did not have a safe or happy future. Imagine my being a Forum Leader here and biting my tongue at work to keep from bawling her out on several points. With a friend, it’s much easier to talk, but I agree that you want to be very gentle in your approach.