No, I'm not going to lie to Him. She's holy as all true believers are.
And just why would he ask me what I thought of His mother? Is there an entrance exam to get into heaven?
The RCC is wrong. Mary was a fallible human being who needed a savior, by her own admission. She was human, and since she had a human father, she had a sin nature and sinned, just like the rest of us.
You are thinking as a human thinks, and not as God thinks.
God saw that Jesus would die and that grace was given to Mary in advance — since he also saw that she would be the Mother of Jesus, true God and true man.
Please do read some of the Catholic apologetics, and try to understand it.
You are thinking as a human thinks, and not as God thinks.
God is outside of time — anything is possible with him.
So, what is needed for Salvation, to be 100% right on all doctrinal and dogmatic issues, or to have Faith?