Ask her how it would work if you would both just do whatever you felt like doing and if she thinks you're doing something wrong, she'll tell you to stop and you will.
Here.. the key is to turn her on to make her want to move on to the next level before she could say stop. TEASE her into wanting more. if the next step is to touch her breasts, then touch her back, her sides, her stomach, kiss her collarbone.. get REALLY close with your hands then move away for a few minutes and shift to her back again.. repeat a few times. when you feel she's ready, you go for grabbing her breast, also slow and probing. same goes for absolutely everything else.
women take about 20-30 minutes longer than men to get turned on, so if you make HER wait past those 20-30 minutes.. she's yours.