Why are the children, Ignorance and Want, described as being old before their time?

In 'A Christmas Carol', the children Ignorance and Want are described as being old before their time because of the abuse and harm they faced as a result of the apathetic affluent class and the uncaring British government.

The children have faced so many hardships and, like Tiny Tim, Bob Cratchit's son, they were forced to live on small earnings and a lack of education as a result of the extreme stratification of Victorian societies. The child Ignorance demonstrates the lack of education young children faced, which they should not have, whilst Want represents the need of the poverty-stricken people for good and basic necessities as all had been taken from them.

They are experiencing hardships that children of their age should not face, especially so young.