Weight loss plan for 50 Y old mother who works full time?

The ketogenic diet is the best way to go. It's free and there is a lot of info online. Josh Axe Diet Doctor Keto for Beginners is a good place to start. and here is the link:

https://draxe.com/nutrition/guide-to-keto-diet-for...

This is a healthy diet, it even reverses illnesses and/or improves them. He also has a book about Keto which is great.

Why sign your mother up for a weight loss clinic? It's a waste of time and money.

there are also Keto facebook groups out there for support.

Nothing is going to work if your mother isn't willing to follow it.  She doesn't need a clinic.  She needs a change of attitude.

Your mother doesn't want to change. She doesn't want to try new things. She doesn't honestly believe that her diet and her weight are impacting her health.  The reality is that just about any type of calorie deficit eating plan that also provides essential nutrients will work for weight/fat loss.  It can be something like Weight Watchers or something like a keto plan.  The key is learning portion control and choosing foods that provide nutrients within the person's calorie limit. While getting some form of daily exercise is great, weight loss and management is 80% diet. I'd suggest that you and your mother read a couple of books like The Longevity Paradox by Dr. Steven Gundry.  He lays out a pretty convincing argument backed by clinical data of how food choices directly impact health.  It might be too technical, but worth a try.  

To be honest nothing will work unless she makes the decision herself. I would encourage her to do something physical first before making diet changes (20 years are some hard habits to break). So suggest going for walks or jogs, maybe swimming or whatever activity she may enjoy and can perform safely