I dunno - I'm not defending them when they put her PBs on their insta or whatever, but I do think they are a little bit stuck. If they drop her as a client, that doesn't help her either - she'd just go elsewhere probably to someone (even more) unscrupulous. And they can hardly say anything publicly or to a stranger that is in any way revealing of personal info. I don't know what the best thing for them to do would actually be?
Personally, I believe that the most ethical option would be anything other than what they're currently doing.
There's a difference between supporting a struggling athlete and endorsing the eating disorder of an individual who has been shown to have zero willingness to change, and absolutely no care for anyone other than herself. If they want to keep working with her, they should decrease the volume in her plans until she commits to fuelling properly and if she doesn't like it she can say goodbye.
That wouldn't be the preferential option though. She needs to realise that there are consequences to her actions, and if the physical ones don't come soon enough then it's up to her coaches to make the most ethical choice and stop promoting her toxic influence. What they're doing now is parading her as an example when she is clearly unhealthy physically and selfish/inconsiderate mentally. They should not associate with her in that way. If she goes to someone supposedly worse then that's her choice, but at least then Purdue Performance aren't responsible in any direct way for enabling her disorder.
As it is she will never change. She gets the headpats and publicity of working with them and they keep giving her more and more intense plans, while ignoring the extra she often does on top of an already gruelling regime. It's utterly negligent and they're the prime example of why there's more regulation needed when it comes to online trainers and coaches of all kinds; not just running, but nutrition and bodybuilding or powerlifting prep and comps too.