She looks gravid, or else just really really well-fed. Is the other newt(s) male or female?
The white clouds will not bother newt eggs.
I think you can (probably should) raise the water level in the tank. The more water, the more stable the water quality is. Adult ensicauda rarely need to leave the water, and they are quite happy in deep water. Maybe you could put some kind of platform under the waterfall/filter device to raise it up higher. Otherwise, your setup looks nice.