Depression is sadly common among epileptics. It can be a side effect of medications but more often it is just having to live the way we do. The compromised lifestyle that a lot of us face can be disheartening and leads down a spiral of depression. I am 24 and have my seizures pretty much under control but I still am unable to live a normal life. Covid hasn't made things easier.
Everyone is different but I would say just dont try to push her too hard. Be there for her and let her know you love her and want to be there for her. If it gets worse it is good to let her neurologist know and they may recommend seeing psychiatrist. We are all different, but often have overlaps. I hope your daughter feels better soon.

Being confined to an extent like we are with epilepsy is bad enough but to be confined in more than one way is a surefire way to cause depression. I had surgery and have total control of seizures but the depression hits me once in a while. Since last March, it's been stronger and more frequent. I just look for the positive side of what's happened lately and try to keep my mind on that.