answer:Yes, it is neglect. It’s hard to give you advice as I don’t what the country or culture is where she lives with your parents. In the US, Canada, or the UK, i wold recommend getting ahold of the appropriate authorities to make sure she is fed properly and has some structure and routine. Would your grandparents be willing to take her in? It sounds like your parents wouldn’t even miss her. Or is it possible for her to emigrate and live with you?