A lot of people mistakenly believe that you get a bigger glove as you get older.
Actually, the difference between a youth glove and an adult glove is the size of the inside, not the outside. An adult glove is made to fit a larger hand, a youth glove a smaller hand.
The outside size of the glove is chosen based on the player's position. Typically a 2B uses the smallest glove on the field, OF the largest. (1B and C use specially designed mitts, of course.) Different pitchers use different sized gloves based on their preferences between hiding the ball better (larger glove) or acting as a Maddux-type 5th infielder (SS/3B size glove).
Your daughter will no doubt still need a glove designed for youth. Choose the outer size based on her position. If she is still young enough that her coach is still letting the kids try all the positions, try a glove sized for SS as that is more versatile.
Also make sure you have a glove designed for softball. A softball glove has a larger pocket than a baseball glove. If you're using a youth baseball glove for softball, this may be why the ball is popping out.
