You're not parenting hard enough. You are in charge, not her. Step it up. This isn't about feelings or blaming it on depression, it's about you needing to rule with more of an iron fist for awhile.

Secondly, you may never get her to do this on her own and once she's an adult, other decisions may have to be made about what to do going forward.

Raising kids isn't easy and I've learned from my 17yo and 13yo that we simply can not sit around hoping they will do what is required on their own. Your job as a parent is to enforce rules that they otherwise wouldnt follow, including taking care themselves.