I think you read that wrong. That quote (”and you wonder why a lot of Roman Catholics are leaving the church”) is from her husband not the priest who refused to hear her Confession.
I did a bit of a double take myself, I too initially thought her priest said that too.
You’re right, I did miss that detail. I apologize.
The point remains (though it should be directed to the husband. I apologize, Father!)
However, one of the 6 precepts of the church (prior to Vatican II revisions I suppose) states:
6. To never violate the laws concerning the Sacrament of Matrimony.
And that includes a prohibition against marrying a non-Catholic. (See http://www.shrineofsaintjude.net/homemx.html)