Young woman is a perfectly correct translation of the Hebrew Almah.
Maybe in some context other than Holy Writ.
It implies virgin, but does not necessarily mean virgin.
If it implies virgin in the text then it should be translated virgin.
It is prophecy of the Blessed Virgin, to change it to "young woman" is an assault on Catholic doctrine.
They are not changing the New Testament reference, which quotes from the Greek Old Testament and uses the word parthenos, which does mean virgin.
That would be too blatant even for them.
The problem most people here will have with this is that they are using the Hebrew test, not the Vulgate.
No, that's not the problem at all. The problem is that they are using a translation that does not accord with Catholic doctrine but on the contrary agrees with those (the Jews) who attack Catholic doctrine.