Have you signed any loan papers? If not, you have no financial interest in the home.
Does you name appear on the deed to the house? If not, you do not have any interest.
They are looking for monthly income from your investments. This is not so for you, as you do not have any income coming in as a result of your shared home.
Unless the money the mother is paying is being reported as income, and you DO have financial ties to the house?
Answer the above questions, and you will be able to answer the questionnaire.