This is one of my biggest pet-peeves!
Muscle is more dense than fat...and the same weight of muscle takes up less volume than fat...so yes, you can be getting smaller and still weigh the same because a muscular size 8 woman weighs more than a fatty size 8 woman (all other things being equal, of course).
But yes, a pound of muscle weighs the same as a pound of fat.
Edited to answer the OP question:
I read somewhere that the average woman can gain about 1/4 lb of muscle in a month. It's very hard to put on actual muscle mass. That said, someone who is new to strength training is going to see faster gains than someone who is experienced. And your muscles can definitely get stronger faster than that 1/4 lb might indicate. If you are feeling better and looking better, isn't that what matters the most?![]()