If you enjoy writing, keep writing. Even if she's right and your writing is horrible, then that doesn't mean it will continue to be horrible, we all have to start somewhere. Plus, if it was a first draft then most first drafts suck. Mine certainly do, and I've seen first drafts from bestselling authors that weren't very good either.
Also, if your goal isn't to publish and get a bunch of readers, then who says it has to be good? If writing makes you happy, then do it for the sheer pleasure of it. I once knew an amateur writer whose writing was awful and who, while very active in writing workshops, never listened to any writing advice. He'd continue to write these long, tedious, telling reads that nobody but himself seemed to love, but that was enough for him.He sadly passed away some years ago and never did get published, but he'd spent thousands of hours doing what he loved and he made a lot of friends in the writing community. We all miss him, if not his writing. That's not too shabby a way to spend your time, I think. I'm sure writing gave him much more joy than reading, watching TV etc.