The friend who told you not to lift doesn't know what he (or she) is talking about. Your second friend is correct.
You cannot "bulk up" while you're in a calorie deficit (which is what you're doing if you're losing weight). And you can't really "bulk up" if you're a woman, anyway. You don't have the natural testosterone to "bulk" w/out putting some serious effort into it.
When you lose weight, you lose fat and lean muscle mass. It's unpreventable - you just do. However you can minimize the loss of the lean muscle mass by lifting weights and/or doing body resistance work to build strength, which will put you in a much better place as you lose the fat.
Muscle is less dense than fat and it is more metabolically active ... so maintaining muscle while you lose fat is the absolute best thing you can do for yourself.