The quads (if they all survive) will have a lot of older brothers and sisters, who will make an extended family to help look after them if their parents find it too much, and give a younger perspective as they grow up. The lack of grandparents will be counteracted in a way by having older parents.
In previous centuries, when maternal mortality was far greater, and parents in general died younger than they do today, the equivalent was probably the late child born to a woman in her forties. Those children were brought up by older siblings, and did OK.
My own mother was 20 when her little sister was born (her mother was 45) and saw a great deal of her, to the extent that she and I (5 years younger) were often taken for sisters, not aunt and niece. Still are, to tell the truth.
It is not something that I would do - I have had my turn and that was enough - but we are all different.