A. Although the bell curve for most babies to be done with reflux (spitting up) is around six months, some still have it until the first year of life (and a few beyond that).
If she is spitting up effortlessly, it is not uncomfortable, and she is gaining weight, it is a matter of cleaning up and being patient for it to resolve on its own. Solid foods help since they are heavier and stay down. Thicker formula using pre-thickened products, like Enfamil AR or Similac SR, or adding a thickening agent like Simply Thick to expressed breast milk may also help keep things down for the same reason–you are using gravity to your advantage. It helps to keep your baby upright after feedings for at least 20 minutes also–so the food can leave the stomach and enter the small intestine (so it won’t come back up).
If the spitting up is entirely new for your baby at 9 months of age, if she is uncomfortable, avoiding meals, or not gaining weight, then you need to check in with her doctor.