My mother does the cooking in my family.

Does your mother do the cooking in my family ?

陈述句里的do是作为动词，是不能提到句首的，因此要加个助动词，your mother 是三人称单数所以加does.加了does后动词要改为原型。

Does your mother do the cooking in your family?

DO your mother do the cooking in your family?

Does your motherdo the cooking in your family?

Does your mother do the cooking in your family.

你妈妈在你家里做饭吗？

Does your mother do the cooking in you family?