How big each person gets is determined by genetics and training. But primarily genetics.
Females, unaided, will not get as big as men becasue we have about 1/10th the amount of testosterone. Testosterone is the primary muscle-building agent.
MOST PROFESSIONAL (and many non-pros) female bodybuilders, fitness competitors, even figure competitors use some form of AAS (Anabolic Androgenous Steroid - "steroids"). How much and what kind depends on their level, their goals, and their genetics. I consider it pretty safe to say, if you know their name, they do some form of AAS. If you see their pictures regularly in the magazines, they do some form of AAS. If they are an IFBB Pro, they are likely doing some form of AAS. NOT EVERYONE, but MOST.
AAS is how they build their muscle. It *is* possible to be natural and build muscle. It is just harder and takes MUCH longer. Sounds like you are on the right track with your diet. But it is going to take time...lots and lots of time.