You can count the segments on the bottom of the abdomen. Six is female and male is eight. If the abdomen is chonky then it's most likely a female as well. Apparently the females of this species are much bigger than the males and has a different leaf appearance as well. This is from the Wiki, "Acanthops species have an unusual degree of sexual dimorphism compared to other mantids. The flightless female resembles a curled dead leaf folded back on itself, and weighs twice as much as the males do. It has reduced wings that can be raised to reveal bright warning colors on the abdomen. The male has long functional wings that resemble a flat or rolled-up dead leaf at rest. When perched, males often assume a posture where the head, grasping legs and prothorax add to the camouflage effect by recreating the appearance of a dead leaf's shriveled petiole and stipules". Hope this helps.