Here is a good chest workout for women. This workout has three exercises you can do 3 sets of 10 repetitions with 1 to 2 minute rest in between sets. This workout is also good for your core which will help with your posture.
1. Swiss-ball dumbbell chest press
Grab a pair of dumbbells and lie on your back on a swiss ball.
Raise your hips so that your body forms a straight line from your knees to your shoulders.
Your palms should be facing out, but turned slightly inward.
Without changing the angle of your hands, lower the dumbbells to the sides of the chest.
Pause, then press the weights back up to the starting position as quickly as you can.
Straighten your arms completely at the top of each repetition.
2. Machine chest flyes
When setting the seat height, make sure your shoulders are in line with, or slightly above, the level of the handles. This will help ease strain on your shoulders and direct most of the work to your chest. With the bent-arm version, position your elbows against the pads and lightly grasp the handles. If you’re using the straight handles, simply grab the handles. Then contract your chest to bring your arms across the front of your body before slowly returning the weight to the starting position.
3. Stability ball push up.
Get on your knees like you were about to do a regular knee-push up and place your hands approximately shoulder-width apart on a stability ball place in front of you. Keeping your body straight and abdominals braced tight, begin by bending your elbows and lowering your body down toward the ball, chest first. Pause at your lowest point and then press back up to the starting position.