You’re in a difficult position. Have you talked with your spiritual director about this? I think you should, for your own sake.
One of my close friends, who was raised Catholic but hasn’t practiced since leaving the family home, has been undergoing IVF. In her first round, 17 embryos were created in vitro; 16 died and 1 blastocyst is in a freezer. She and her husband have already lost at least 16 children! The failure rate of IVF is sufficiently high that the loss of at least one embryo per round is effectively inevitable. That’s unconscionable!
When my friend first began the IVF process, she asked my opinion. I said that, as a Catholic, I believe that IVF isn’t permissible, even if there was a guarantee of no loss of life. I acknowledged that I could only imagine the pain of not being able to naturally conceive a child and felt tremendous sympathy for her, as she has always dreamed of having a large biological family. I also spoke of how hard it would be to struggle with the Church’s teaching if I were in her place.
Family is, understandably, constantly on my friend’s mind, and she shares her updates with me when we get together. I struggle to provide the appropriate support for her, and have attempted to separate support for the cross of infertility from encouraging or condoning IVF. The latter I cannot do. That she and her husband are unable to have a child is sad, and I can share in that with her. I pray every day that she and her husband will adopt instead of pursuing IVF. They are deeply hurting at the inability to conceive their own child and their (understandable) sense of personal loss is clouding their moral judgment. Good people do some horrible things when in pain, and I want to be a lifeline to the Church for my friend.
I don’t know what the most ethical answer is to the situation of your friend having a frozen embryo. I’m not a bioethicist. I do know that the parental desire to have a child doesn’t trump a child’s right to a) life and b) natural conception. A child is a unique person created by God from conception and, as such, does not deserve to be reduced to the object of parental desire, no matter how seemingly altruistic that desire is.
You are in my prayers, as are all of your friend’s children.