Who told you this? Catholics are free to interpret what they will out of the Bible unless is goes AGAINST Catholic teaching and as long as they don’t deny what Catholics Teach.
Now, the Church has taught that the woman represents:
Mary, Israel, AND the Church all at the same time. There has been no dogmatic statements to this effect.
You must understand, the Church doesn’t declare something dogmatic until there is such a dispute about it, that it cause an uproar. That’s why Transubstantiation and Purgatory were so late in the Church’s History - There was no argument against these teachings.
Just because they teach one thing, does not deny that it can ALSO be another.
Remember, the Church teaches that Mary is a type of Israel, and Mary is a type of the Church (or is it Israel and the Church are types of Mary). These case that the woman is Mary does not deny that the woman is the Church.
There are multiple fulfillments to numerous Scriptures. Take a look at Isaiah 7:14. This prophecy was fulfilled in Isaiah’s time, and then later fulfilled in Jesus.