It's more the thumb and fingers that need to be aligned to hit both spots at once.

Oh also, instead of just hammering away at rubbing them, vary your actions. Like move your thumb and fingers as if you're manipulating a ball, move from side to side, switch to your tongue on the clit for a bit, pull your fingers out and rub her whole labia with your palm, alternatively tease and satisfy, have your other hand roam her body (and not just the fun parts, but arms, shoulders, legs, neck, head, belly, back, sides, hands). Try to think of all the ways you can show physical affection and do them (just don't race through the list, it's about having a variety of behaviours to keep things interesting, not checking things off a list).