My pup ain't liking KONG toy all that much?

i have a bet pup, and i bougth her a kong toy.a smaller one.but i should have bought her a bigger one.anyway, i stuffed it with peanut err and her royal canin food,and freezed it.and i got to tell u, it seems to me like that toy is a little stupid.its very hard for her to grab the food.and when i fill it with dry food only, it is falling out too easily and to quickly.is this toy just allitle stupid, ar can u give me some cipeie for it.or should i buy bigger one.my bet is little over 4 month old.