The eating disorder could be causing her depression. If the body is deprived of nutrients, it will affect the person emotionally and physically. My cousin has an eating disorder and she kept quiting employment and getting new employment and was crying a lot at work. It was not the job, it was the starving of her body causing her to cry at work. She wasn't able to handle any problems that came up. When children do not eat for awhile, they cry because they are hungry. Symptoms of anorexia is hair loss (lots of it), development of peach like body hair, bad teeth, emotional problems, stomach problems, heart problems, etc. She needs help. She will intitially be upset about it, but eventually she will get over it.
I read both posts and I can only say she is in need of immediate psychiatric help. I would suggest going with her to the local mental health clinic for support. Perhaps if there are other people that know her you can enlist their help as well. If this doesn't work out she could be hospitalized just for the fact she is suicidal and injurious to herself but see if you can encourage her in a supportive manner to seek psychiatric help because it will help with her recovery. Before I recovered I did need to be hospitalized a few times and she is safer there than what is going on now. They would treat her and release her after insuring she is safe. There are crisis lines you could call on her behalf but try to work with her first to seek help as you know her as a friend.