I finally stopped laughing ... I really had a hard time believing you actually asked this:
If Jesus having brothers and sisters is the only evidence you have that Mary had other children( which it is ) then you have no evidence which would stand up in any real court.
But only mock trails which is like the trial Jesus went through.
This is nothing but a Catholic and Protestant war and has nothing to do with any proof but only something to bash each other about.
With Christians like this we sure in the hell don`t need any anti Christians.
I don`t know if Mary had other children or not, i am simply saying i see no proof that would hold up to any logical argument so i am of the opinion she did not.
If you think she did then fine but why try to turn opinions into facts which are not there.
If the Bible does not say it in plain words, please don`t preach it to me.
But for me, the Bible does say it in plain language. Mary and His brothers went to seek an audience with Him at a house where He was teaching. That’s plain enough for me. Sorry it does not meet your requirement for substantiation, but it is plain Koine Greek.
BTW, I was laughing at the following: “... why would they be referred to as Jesus`s brothers and sisters if they were Mary`s children?”