As one of the few women in our karate school (often the only one in class), our Sensei sometimes says something about "you hit like a girl" or "you kick like a girl" and I usually chime in with "they're THAT strong?!?!?"
That's fantastic. Damn this fo is good for stocking up on come-backs!
for me the critical things about the form on pushups is keeping your body in a line, lowering far enough (chest touching) and as far as arms go - point to 4 & 8 not 3 & 9 for good shoulders - just like an upside down BP.