You need carbs and even fat to lose weight, it is not healthy to cut out carbs completely, just substitute for carbs which release energy more slowly, like brown rice, wholemeal bread and pasta. Portions of rice and pasta should be able to fit in the palm of your hand.
Bear in mind, if you are not eating enough, your body will go into "starvation mode" and your metabolism will slow down, so you will find weight loss will be slow. The average woman needs 2000 calories per day, if you are looking to lose weight, you can reduce this by up to 500 calories daily.
Do not rely on what the gym machines tell you regarding calories being burned, this is not necessarily accurate. You only need spend 30-40 minutes doing CV work, 3-4 times per week, just ensure your heartrate remains in the specified zone for that time.
Lots of women don't want to do weights, as they are under the false assumption, they will get muscular. Doing weights is very important, as I keep telling people here, the more lean muscle your body has, the more bodyfat will be used as fuel and your metabolism will speed up.
Speak to an Instructor at your gym and get them to do a Resistance (weights) programme for you, which should also be done three times per week. Ideally you shouldn't be doing exactly the same weights or working the same body parts on consecutive days.