This problem is not unusual. It seems like just about everyone has trouble with numbers or letters at some point. First off, how old is your daughter? If she is preschool or kindergarten-age, it's normal to still be learning numbers. One of the things I would suggest is to look for fun ways to explore numbers that aren't all about drilling or doing "work." I recommend Education.com's activities, which you can sort by grade and drill down to find only activities that have to do with learning numbers (I've attached a link to the preschool numbers activities, but you can change the grade according to your daughter's age).
Sometimes all it takes is to make de-stress learning and make it fun, as well as to take it out of the classroom and make it part of a child's time at home as well.
You would have to make counting or any games that involve numbers interactive and fun for your daughter. Create interesting games with numbers.
Our toddler learned his numbers at a very early age. I used to count on my hands and we used to play games with numbers on the computer. We had Baby First TV which had programs with counting and numbers.
We bought him a large exercise mat made from sponge numbers and he loved it. When we read stories to him, we ask him to count how many animals he sees or how many trees or butterflies. Even when we are in the car, I would ask him to count the number of cars or buses or trees he sees. Every opportunity we had we used to help him with his numbers.
You could play a game with numbers with your daughter and ask her to identify the numbers on the mat. Or you could find other number games that are specific for her age.