I think everybody reacts differently to chelating. It's really hard sometimes to know what's "typical."
My friend, for example, has been chelating and she's been gaining weight too.
I gained weight as well, but this was after I had lost too much weight while following an anti-yeast diet. My weight stabilized after some months of chelating. I began breaking the diet a lot recently, and I began gaining weight again. When I did an anti-yeast program for a couple of weeks, my weight dropped again. Actually, I think my "weight gain" was mainly yeast-related bloating which went away after the yeast cleansing.