Pigeon learning how to eat seeds

Hi, i have a 4 weeks old crested pigeon and i wnat to know when i can fully depend on her eating on her own, i cant really check the crop that well and see if shes eating the seeds bc shes mostly fully feathered, she does peck at the ground and stuff and when i place seeds she just hits them and causes a mess without really eating them((pushing them around), also ive noticed shes hitting her beak on a sandlike surface near her cage i wnat to know if thats bad or if shes just like filing her beak down or smth