How can you make a 9 month baby stop sucking her fingers?

Well a 9 month old baby may still need to suck his/her fingers. Babies suck on fingers and pacifiers for security. They somehow need it. If you want to get a baby to stop sucking his/her fingers, give him/her a pacifier to suck on instead. Or keep him/her occupied so whenever he/she sucks on her fingers, give him/her a toy to play with.