Answer:
Start very slowly and gently by placing your hand over her vulva. Use your fingers to gently stroke and caress her outer and inner lips, using gentle up and down movements. Locate her clitoris at the top of her labia and circle it gently at first with your first finger.
Be guided by her responses. If she is enjoying it you will hear her breathing change and she may vocalize her enjoyment. You will also notice her becoming increasingly wet and her labia will start 'opening up'. Wait until she is ready (very wet) before you slip a finger inside her.
Continue stimulating her clitoris while you put your fingers inside. Once inside curve your fingers as if you are signalling someone to 'come here'. Increase the speed of your 'come hither' fingers if she responds positively. You will feel her vagina contract around your fingers as she becomes more turned on and nears orgasm.
Don't be rough and don't do anything if she is dry. You may want to use a lubricant to help things along.