How can I handle kids of different age group like I have three kids 14,12,4

I think, kids, ageing 14, and 12 would be company for each other and they can spend the whole day chatting if allowed, else you can give them books to read. And for four year old, I think you can stock up colouring books, as kids this age like to colour a lot. Atleast my kid really is fond of it. Or the kids 12 and 14 can keep the child engaged. My niece is 14 and when my daughter, 5 and his another cousin 6 are together, she keeps these little ones busy with her. I do not know how she does the trick but they love to hang around with her and she also doesn't get bothered, atleast for 2 or 3 hours.