Speaking from experience i can tell you the last thing you want to hear is that you need to eat more. I understand that is hard to stand there and watch her disappear in size. The best thing to do is reassure that everything will work out and try to help her relief some stress so that she'll begin to eat normal again. Also a good time to gain weight is by eating at night. When i got lost 20 pounds in a matter of weeks to which i couldn't afford to lose my boyfriend but me on a gain weight diet by making something for me to eat at night, from milk shakes to frozen pizza. I wish you the best of luck and if you needed so addition comments don't be afraid to email me!!!