My sister is morbidly obese—the doctor’s words, not mine. She has diabetes, among other health problems, and now has to have her leg amputated. I don't want to hurt her feelings, but honestly, I’m not physically able to care for her. I already do a bit for our mother, who’s in an assisted living home.

I suggested that my sister hire a male home care aide for after the surgery because I felt he could do more for her than I could — that turned into a huge blowup between us. It’s just like in the past when I’ve talked to her about losing weight or having a surgical procedure: She gets mad, pouts, and won’t speak to me for weeks.

How do I get through to her but still salvage our relationship?

You're truly in a rough spot, caring for two family members. But know that it’s not all up to you. It may help to think of yourself more as "coordinator" than "caregiver," especially with your sister. Your primary role, after all, is family member. You can hire help, but you can't hire a sister or a mother.

Focus on your sister’s overall well-being more than her day-to-day care needs. If the reality is that a strong outside caregiver can better help her, then treat that as a matter-of-fact need.

Your sister’s not going to change her ways until she deals with some very deep issues -- and that’s up to her. The more you push, beg, or fight, the more she’ll have to rebel against. The very best thing you can do for her is to encourage her to talk to a professional, a trained and neutral third party who can help guide her to healing.

Loving someone unconditionally doesn't mean that you don't have to accept the fact that she’s harming herself. Do some research to find someone great. Two places to start: Overeaters Anonymous or an eating disorder specialist. Find someone your sister will respect and can open up to. Obesity often has to do with unresolved issues, such as childhood traumas, sex abuse, or depression, to name but a few. (For insights, check out the phenomenal book, Women, Food, and God by Geneen Roth.) Do all you can to arrange the connection -- even if the expert needs to come to the house initially or you need to drive your sister to regular appointments or meetings. (Or, if appropriate, attend them with her.) It sounds like a lot of effort, but it could save her life.

It’s even possible that, as her sister, you hold some keys to finding those deep sorrows buried in childhood and adolescence. What if her road to healing is also your road to healing? What if her getting well could help your entire family? The more you look at her health as a “family thing” the less it may feel like the two of you are at odds.

When talking to her about her health, make sure you’re not using shaming language or facial expressions. This isn’t about looks. See past them to the person she really is. Keep a mental picture in your mind of your sister happy and healthy.

It’s going to take a lot of guts, willpower, strength, and staying power to get through this. She needs you not simply to lift her, but to help her have the courage to face some tough things and find her own way. You’re going to have to be her example not only in the way you eat, move, and live, but in your perseverance to get help.

At times you might be tempted to just let her handle it; after all, she got herself into this state. Fight those feelings, especially when she has a setback. Show her you’re in this for the long haul and that you won’t give up. You can’t and you won’t. That’s love. And I promise you that as painful as it’s going to get, it’ll be worth it.