So sorry your daughter is not well. My advice would be to learn as much as you can about the disorder.
A great book to start with would be:
When Your Teen Has an Eating Disorder: Practical Strategies to Help Your Teen Recover from Anorexia, Bulimia, and Binge Eating by Dr. Lauren Mulheim.
I'll try to answer your questions:
1. How are you handling socializing, like going to parties, sleep overs, and school events?
We did not restrict socializing. I did try as much as possible to make sure that meals were eaten before she went out and if she was at a friends house I sometimes went and got her at mealtimes, fed her and then brought her back. (I had to assume that she was not eating on her own). When she finally was in recovery all meals were eaten at home for a long period of time.
2. How have you handled supervision at school?
I was rather clueless during my d's illness during high school, so there was no supervision during lunch. As a result she later admitted she spent many lunch hours in the library studying and not having any lunch. So I guess my advice here is don't be like me. I was at work during the day and never dreamed that she wasn't eating her lunch.
3. Is there a time when relapse is typical after a period of doing well? What is the timeframe for this?
I don't think there is a real time frame because it not a one size fits all illness. Vigilance is necessary for a long time. Sometimes what seems like a relapse just indicates that the person was never recovered but still working on remission. Recovery is not a straight line and there may be steps forward and backward.
Our d is 14 and has just been diagnosed with purge disorder with restrictive eating. We have seen some excellent providers and are on the road to recovery.
Typically it takes awhile for recovery to kick in. Feeding 3 meals a day with a couple of snacks, and making sure that your daughter cannot visit the bathroom after meals might be the first steps. If she eats 3 balanced meals and a couple of snacks during the day it may help her not want to binge since she will not be hungry. What type of treatment is your family and daughter participating in?
She has never lost any weight at all. She just was super restrictive about what she ate and occasionally purged if she felt like it was a "binge". Of course, what a "binge" is varies from one child to the next. We never noticed a single hint of weight loss. Do you think this changes the "severity" of her situation?
I don't think that not losing weight or noticing weight loss changes the severity of her situation.
Purging is very serious and can lead to dangerous health complications. Low potassium can affect the heart for example. It can ruin the enamel on the teeth and cause harm to the esophagus. Has your daughter had labs done to check her electrolytes? The behavior really needs to be stopped as soon as possible. One thing to understand is that teens who purge often lie about it. Supervision is key. Not allowing a child to go to the bathroom after eating for a long period of time (many months) has worked for some families.
Do you have your daughter's historical weight and height charts from her pediatrician? Can you chart her growth curve and see whether she is still on it? In order to stay on her curve she will need to be gaining throughout her teen years.
May I ask how you handled snacks or eating between meals? How much supervision is needed there?
We could not assume our child was eating unless we saw her eating, unfortunately. So the answer to that question is as much supervision as possible.
We are here to answer any questions you might have and to encourage you as you help your daughter navigate through this illness.