No, I will not keep my mouth closed. I am a defender o fmy faith until the day I die. Unlike people who don’t stick up for their Catholic church, I cannot sit there and be ridiculed by anyone. I will say what I know and that’s that.
If you think she’s calm enough now to have a rational discussion, you might want to gently bring up the subject again. Tell her you are open to hearing the truth, and you are sure that she, as a good Christian, is open to hearing it as well.
(This, BTW, is a strategy that has never failed me. Not once has a person ever disagreed with me when I slip a compliment into the discussion. I mean, she’s not going to tell you “No, I’m not a good Christian” or “No, I’m not open to hearing the truth.”)
Then ask her where the Bible came from. Ask her who decided which books should be in it, and when that decision was made. (For example, someone decided the gospel of Matthew belongs in the Bible and the gospel of Thomas doesn’t.) At the very least, this should get her thinking about it.
If she turns the question around on you, just say, "Well, I always heard the Catholic Church put it together. (Notice that this way it’s not you vs. her. It’s “what I heard” vs. her.) Tell her that if you’re wrong, you want to know. But, of course, in order to “prove you wrong,” she’ll have to research the subject.
Always, always, always frame things in the form of a question. Not only does it put the burden of proof on her, it’s far less threatening. You’ll also force her to examine the reasons for her beliefs.
And if she tells you something that sounds off, just say you want to look into it and get back to her about it later. Then bring it here. There are many knowledgable Catholics who can help you learn how to answer any objection she might raise.
I also highly recommend the free downloads at:
biblechristiansociety.com/download
Start with the very first one, “Apologetics for the Scripturally Challenged.” This discusses techniques for engaging in Catholic apologetics. At the very least, give this one a listen before you engage her in discussion again.
Hope this helps!