No matter what the IP diet "educational material" tells you fat loss is an equation of energy. Energy is measured in calories.
On the IP diet you're consuming 700-900 calories a day. As a 5'1" female your energy needs are far less than a 400lb 6'4" male and yet you're consuming the same aproximate number of calories. So of course you're going to be losing fat far slower than someone much larger.
Regardless - as Kaplods pointed out - you're actually losing fat very fat for your size.


