If you want snowshoes that are suitable for most conditions then choose ones where your weight falls in the middle, vs the top end. For example, according to Tubbs' sizing the 21W is suitable for women weighing up to 150 lbs (68 kg), while the 25W size is suitable for weights from 120 - 200 lbs (54 - 91 kg). If you weigh 145 lbs I'd recommend the 25W size. That allows for your pack weight and will provide you with better flotation in deeper snow.