4 years baby trouble in sleeping&eating.

Hi, I have a niece she is 4 years old she don't eat properly nor she sleep. She doesn't eat vegetables nor any fruit she has so much trouble in eating but if we give her mobile with cartoon she just watch the cartoo n and eat, she just like to eat pancakes, chocolates , chips, frooti and Maggi. she like ladies finger and potatoes, doesn't eat other veges and her father always bring her chocolate and chips and frooti that's what she eat daily and also she likes milk . Her sleeping time and duration is very bad she don't sleep at afternoon and night she wake up till 12 and sometime till 1 and woke up early in the morning like 6,7 or 8 am. She is may be 12 kg or 13 kg. She is active always playing , running . We are worried about her eating and sleeping habbit and don't know how to make her eat and sleep , pls help and advice on her above behavior