There is no medication or food for improving eyesight or to get rid of glasses. If not interested in glasses then you can try a. Contact lens b. Lasik laser as your age is now 7 years so your number will increase now whether you wear glasses or not as number becomes stable at age of 18-20 yrs. Having said that I advise you to eat balanced diet including green vegetables and seasonal fruits for keeping eyes and body healthy. Lasik is a very easy and painless procedure. If you want to get rid of glasses then go for lasik after age of 18 yrs

Please note,  since she is growing,  her number is bound to increase as long as growth happens(till she turns to am adult),  which will be around 21yrs.. U can't arrest the growth,  but what u can definitely do is improve the general health of the eyes..  Give her one raw carrot each day or any other food rich in vitamin A..  Alternatively please check for yoga exercises for the eye which will help in the overall health of the eye..