Yes, you decided: the boy will have more fun with a little brother than a sister, or better, with an older brother. But how to do it? You examibe better the flashlight, spotting a button that you never noticed before: the "ac" setting. Maybe "ac" means "age change"? You're about to discover it. You moved the switch on "+", then, keeping the blue color and choosing the "or" setting on the first switch, you shine the little girl again. This time the change was immediate: she shifted, then her height increased noticeably, until she was taller than her brother of about some inches.
Her hair shortened, her face gained a more defined structure and her upper lip showed some peach fuzz.