Most Helpful Girl
it depends on how their relationship is. if him being in her life helps her cope and makes her feel better than forcing him out of her life would be disastrous. she could still get help, and work on her condition with a boyfriend, it just means she has to learn how to set priorities and balance activities.
if he's not being a positive thing in her life, and bringing her down/ not allowing her to focus on her self then they should probably stop seeing each other, or see each other less until she can get herself back on her feet.
Most Helpful Guy
I say its okay that she dates but not before fixing the current crushing thing at hand so rather than cutting off the relationship a forced temporary suspension of the title "dating and relationship" cause both halves seem really invested. and the knowledge that their relationship is suddenly destroyed and a now contact policy I think it would more likely send her mind into a bottomless pit hole of self loathing. And blame her self unintentionally for the whole entire issue as its not 100% her fault for the depression onset. But any contact should be limited to short time. There is no positive for ether of them to loose full contact. Cause what parents never get is that once the depression onset happens they can be counted as the enemy if rash decisions are made. And its not just the lost of trust it can be the full onset of loss of past experences with her own parents. As a result self harm in extreme cases and even the chance of just loosing her entire personality. Her parents may want whats best but removing every thing she's holding onto isn't going to make it better. Tearing away what is the last piece holding her together even if she's toxic isn't going to help her mend scars rather can just lead to a deeper ones. Its touchy but its definitely not worth it if she looses her own identity if its really as bad as it sounds.
Experence: I've watched a friend go down this path lets just say she isn't the girl I remember. It doesn't make it easier that im one of the 3 people she considers friendly other wise she's a very toxic to everyone else including her own family.