Concerned about a co-worker (lengthy)

I have a friend/co-worker that I always kind of looked up too since she did marathons and half triathlons and she has been one of my cheerleaders in my weight loss. She has finally gotten over a torn hamstring and the doctors have allowed her to start working out with weights, and cardio either on the elliptical or swimming. Well she decided to get a trainer since she usually is just a cardio person (I have been with one since Feb). She is telling me the things the trainer had her doing and how she was in pain. I, of course, told her well that is your muscles getting used to working out again it will get better the more you use them. The rest of the conversation went something like this:
Her: “You don’t understand he had me doing this, this and that.”
Me: “Yes I do that with my trainer too.”
Her: “No I have to do them with weights or a kettle ball and on this half ball thing”
Me: “Yeah the Bosu ball. I do that too but usually with a medicine ball.”
It pretty much continued as her trying to one up me to make her feel better since I am over weight and she is at 12% body fat. Yes 12%! They did her over all check with calipers and everything and came out to that while her scale had been telling her 17%.
After a moment of me getting over the 12% body fat the conversation continued with.
Her: “But the trainer finally agreed with me that I am a rectangle since my shoulders and hips are the same width. It’s good to know I am not crazy about that as I thought I was since he agrees with me.”
Me: “Well since you are 12% body fat unless you have a waist that goes in you will be a rectangle. You already said you don’t want to have boobs so that won’t give you shape.”
Her: “No you don’t understand my hips can’t get any smaller, they are already at the bone.”
Me: “Yes I understand your hips can’t get smaller but to get shape you would need to emphasize your waist more. Bring in your sides. Maybe gain some weight.”
Her: “No I don’t want to gain weight I still have 5lbs to lose from my thighs.”
That is when I decided to change the whole conversation to something else.

So this morning she asks me how my training session last night went.
Me:”It went great we did legs and core and my trainer gave a little laugh saying she was planning on killing my arms on Friday.”
Her: “I think your arms are like my legs. Constant work and my least favorite.”
Me: “Well my whole body is constant work right now but until I get the fat cushion off you can’t tell”
Her: “Dude your lower calf area is fabulous and I would kill for your knees.”
Me: “Thanks but my knees?”
Her: “I have FAT in the inside of my knees! I can’t get rid of it.”
Me: “Uhhhhh ohhkay.”

I am really thinking she is close to being anorexic and the trainer, if what she is telling me is true, is helping her along that way. I don’t know what I should do since I know it is a mental thing and we all have our body issues but she seems to be going to the extreme. We are work friends so not that close that I can sit her down and say you need to get a grip but I am really concerned. What should I do?