Yes, it is. Applying modern language usages, such as using the brothers and sisters reference as proof that Mary had other children, to Scripture is just false rationalization.
I find it hard to believe that old languages did not have words for brothers and sisters. The terms for brothers and sisters may be loosely used for other things, like is quite common in the black community today, but it is a leap to assume that was their usage. Basing entirely man made doctrines that rely on questionable interpretations of text to avoid conflict is not something I would be comfortable with. It appears that Joseph and Mary were married and had children. If Catholics want to believe otherwise, that’s fine. Just don’t let it get to the point where Mary is a divine figure, which I dare say there are some who do.