Welcome! you sure have come to the right place
I'm also nursing my 7-month old daughter. The recommended weight loss with nursing is less than a half pound a week which I am almost meeting by only reducing my calorie intake a little bit. I've been having some supply issues, but I think that is more from pumping than anything else.
I can't speak for the PINK method. I'm just calorie counting and am down 4 pounds in the last two months. I'm still having a very hard time keeping exercise in my routine.