The Scriptures are not a lie. All have sinned....this means Mary too.Were Adam and Eve born without sin? Did all the angels sin? None were divine.
But I'm not trying to convince or convert, just to enlighten on Catholicism from what little I know of it.
In case you are unaware...Adam and Eve were indeed sinners. Therefore, when scripture states, All have sinned" it is absolutely accurate.
Including Mary.