small athletic woman

[girlygirl]

Hi Im 23 and am very petite.Im 5'2 and only weigh like 90 to 93 pounds. I work out like crazy but only to build muscle. I cant gain fat to save my life. I currently wear a 0 and that doesnt bother me. My legs are only like 16 inches around my thighs. My arms are only like 9 and a half inches around. And thats actually come up from the small 7 inches and 15. My waist is like 26 and my hips and rear is 34. Im looking to add muscle and it seems like just working out alone is not enough. I feel like my legs look like tooth picks and i cant lie i constantly get made fun of. Everyone always says that i will gain weight when i get older But two kids later and still no weight. Im in great health but just am looking to improve my body. Can anyone give me some advice. I would really apprecitate it. Thanks loads Staey