Certainly no reason from scripture to believe Mary was sinless, nor a perpetual virgin.
On the contrary, I suspect she filled God’s design for marriage - and enjoyed it.
I recall a scene where some one comes to Jesus while He was teaching in a house, telling Him that His Mother and Brothers were outside seeking an audience with Him.
I suspect Joseph enjoyed it too, 👍😀 and fathered many children with Mary. 👍👍👍 I suspect Mary, was like most Jews at the time. They didn’t quite understand the true plan of redemption. She obviously knew Jesus did not have a human father, but I think she still didn’t understand it. Even the brothers of Jesus didn’t believe in Him. I think, after the resurrection, they did (James, the head of the Jerusalem church, and Jude) Maybe the resurrection finally clued Mary in as well. We don’t know for sure. We don’t know if all the other brothers and sisters of Jesus became believers. I hope they all did. 😀
If I only had a gun right now...