It depends on the origin of the depression, but since it appears to be chronic, it might be worth a shot.
From my experience, cases of surging depression during MMS treatment are often related to Herxheimer reactions, so the best way to prevent it is to start with low doses, see what happens and increase dosage as long as no ill effects appear, same as with nausea and diarrhea (in a way they stem from the same origin).
As for the second subject, MMS is indeed a bit slow with fungi. I had good results by adding essential oils to the regimen, not sure it will work for you, but again, worth a shot: i'd say 6 drops of
Origanum vulgare kaliteri on a neutral pill or a tablespoon of olive oil, twice a day. If It works for you, halve the doses for your daughter.
I hope it will be useful.