Female doing P90X should I be using protein powder?

no

http://www.ncbi.nlm.nih.gov/pubmed/21289204

your "anabolic window" is more like 24 hours, which would mean it hardly matters how long it takes for you to "replenish" after a workout, unless you plan on eating nothing for a full day afterwards, which in most cases i would highly doubt. nutrient timing is largely irrelevant in terms of body composition, it's already been proven.

oh, and by the way the "evidence" you provided me were just articles without a single reference to any studies whatsoever.

Getting you site your source is exactly what I wanted. Your source simply states how human muscle protein performs for 24 hours after resistance exercise. It does not state whether or not to feed that muscle during that time.

This, however, does.

"These findings indicate that the rate of recovery is coupled with the rate of muscle glycogen replenishment and suggest that recovery supplements should be consumed to optimize muscle glycogen synthesis as well as fluid replacement."
http://www.ncbi.nlm.nih.gov/pubmed/12580650

They ingested the recovery drink immediately after & 2 hours after exercise. Again, as I previously agreed, the specific amount of time is debatable. Nevertheless, the above study did show that the participants' muscles recovered quickly after ingesting a recovery drink. Again, post-workout recovery is necessary.

no

http://www.ncbi.nlm.nih.gov/pubmed/21289204

your "anabolic window" is more like 24 hours, which would mean it hardly matters how long it takes for you to "replenish" after a workout, unless you plan on eating nothing for a full day afterwards, which in most cases i would highly doubt. nutrient timing is largely irrelevant in terms of body composition, it's already been proven.

oh, and by the way the "evidence" you provided me were just articles without a single reference to any studies whatsoever.

Getting you site your source is exactly what I wanted. Your source simply states how human muscle protein performs for 24 hours after resistance exercise. It does not state whether or not to feed that muscle during that time.

This, however, does.

"These findings indicate that the rate of recovery is coupled with the rate of muscle glycogen replenishment and suggest that recovery supplements should be consumed to optimize muscle glycogen synthesis as well as fluid replacement."
http://www.ncbi.nlm.nih.gov/pubmed/12580650

They ingested the recovery drink immediately after & 2 hours after exercise. Again, as I previously agreed, the specific amount of time is debatable. Nevertheless, the above study did show that the participants' muscles recovered quickly after ingesting a recovery drink. Again, post-workout recovery is necessary.

"Enhanced amino acid sensitivity of myofibrillar protein synthesis persists for up to 24 h after resistance exercise in young men."

even the title states the amino acid sensitivity and protein synthesis persists. im pretty sure it's obvious that has to do with consuming nutrients. I have no clue where you got that it doesnt state whether or not to feed the muscle, thats how protein synthesis happens, by CONSUMING protein.

and here is more for you

ANALYSIS OF NUTRIENT TIMING

"When speaking of nutrition for improving body composition or training performance, it's crucial to realize there's an underlying hierarchy of importance. At the top of the hierarchy is total amount of the macronutrients by the end of the day. Distantly below that is the precise timing of those nutrients. With very few exceptions, athletes and active individuals eat multiple times per day. Thus, the majority of their day is spent in the postprandial (fed) rather than a post-absorptive (fasted) state. The vast majority of nutrient timing studies have been done on overnight-fasted subjects put through glycogen depletion protocols, which obviously limits the applicability of the outcomes. Pre-exercise (and/or during-exercise) nutrient intake often has a lingering carry-over effect into the post-exercise period. Throughout the day, there's a constant overlap of meal digestion & nutrient absorption. For this reason, the effectiveness of nutrient timing does not require a high degree of precision." - Alan Aragon, M.S. in Nutrition

ANALYSIS OF GLYCOGEN UTILIZATION DURING TRAINING

"The carbohydrate requirements for weight training actually aren't that great. I did some rough calculations in The Ketogenic Diet and concluded that, for every 2 work sets (assuming a set length of 30-45 seconds) or so, you'll need 5 grams of carbohydrates to replenish the glycogen used." - Lyle McDonald, B.S. in Kinesiology

"In a study by Tesch et al. (1986), nine bodybuilders completed five sets each of front squats, back squats, leg presses, and leg extensions to fatigue, comprising 30 minutes of exercise. Biopsies of muscle samples were obtained from the vastus lateralis before and immediately after exercise. Muscle glycogen concentration was 26% lower post-exercise, a rather modest decline considering the demanding exercise protocol completed. This led the authors to conclude that energy sources in addition to muscle glycogen support heavy resistance training. Data from Essen-Gustavsson and Tesch (1990) with nine bodybuilders performing the same exercise regimen (as above) revealed a 28% decrement in muscle glycogen content as well as a 30% decrease in muscle triglyceride content. This suggests that intramuscular lipolysis (breakdown of triglycerides) may also play a role in energy production during repeated high-intensity exercise. Overall, research suggests that intramuscular glycogen is an important fuel supporting weight training exercise, but not the only substrate."

http://www.ncbi.nlm.nih.gov/pubmed/3758035
http://www.ncbi.nlm.nih.gov/pubmed/2289498

ANALYSIS OF INSULIN AND ANABOLISM / ANTI-CATABOLISM

‎"Insulin appears to exert its anabolic effects chiefly through inhibition of muscle protein breakdown."

Excerpted from the following research:
http://jn.nutrition.org/content/128/2/323S.full

EDIT: oh and just to make it clear, since this might be what you are thinking I am not saying you do not need post workout nutrition, I am stating that it does not matter if you get it immediately after a workout or even within 30 minutes to an hour, as long as you get the nutritents within 24 hours(could be longer, but why take it that far) it won't make a difference, and I can't imagine the vast majority of people waiting longer than a day.