I think pretty much every woman, when they start training (including me) has that problem with not being aggressive enough. As women, we're encouraged to be demure and non-aggressive, so the idea that you have to attack people and follow through on attacks is a bit out of our experience (meanwhile, men have the opposite and are usually too aggressive when they start training).

Here's the thing though - you'll hurt people. They'll hurt you too. If a person hurts you too much, you tell them, and if you hurt them too much, as a good training partner, they should be telling you. This means unless it looks like they broke something, you ripped their skin open, or they look dazed and concussed, you don't need to ask if they're okay. They will tell you if you're hurting them, and if they don't admit to it for whatever reason (usually cause they're being macho) then it's not your problem.