Whey protien?

so i am a women 5"2 147 pounds looking to tone up get some muscle definition i want to lose weight but am not sure if this is possible if i want to get some muscle definition i know muscle weighs more than fat anyway so i have been doing p90x for 4 weeks i took some pics and i see some difference but my stomach still looks like crap so my question is me being a women can i have whey protein shakes two times a day i usualy have one around 1030 am then after my workout which could be anywhere between 8-9 pm. I also wanted to know why my stomach still looks like i have not been working out i have to admitt i am not in bad shape i took kickboxing for 2 years on and off i have had a flat stomach before and i feel that even if i do bust my but working out i still will not get my stomach down. If anyone is familiar with p90x you know this workout is no joke Help i need some advice or opinions oh i also eat the right foods i eat 5 times too so help