I Have A Friend Who's Struggled With An Eating Disorder

I have a friend who's struggled with an eating disorder for 6 years now. She has extremely low blood pressure and at times her heart rate slips to 54, 56. We've been advised that when her blood pressure goes very low, she should drink alot of water....I know she had a particularly hard day today and her pulse was at 56 again.....Should I encourage her to go to ER?