I feel like this is a huge concern - but am I projecting my experiences on it?
Her comments are pretty self-evident -- she is expressing clearly how she feels.
It's good that you are listening.

My child has refused to see the other parent in a few weeks, which I supported - but I know I can't do that forever.
I have 100 percent custody, too. My son hasn't seen his dad for the past 4 years. That's based on court stuff, but S16's choice to not communicate with his dad is his alone. He is self-aware now (thanks to therapy) to realize that his dad is not emotionally safe for him. S16 does consider that one day he might feel differently, but not now.
It's tough to know that his dad is not in his life, but I also look at it like he's getting the therapy and skills to help him for when he's strong enough to have a relationship with his dad again, if he chooses.
Yesterday, my son was in the ER to get a blood transfusion and has a complicated summer of tests and surgeries ahead. These fatherless moments are so painful, but n/BPDx cannot handle stress so reaching out when it's stressful is exactly the wrong time to do so. I mentioned it to S16, and he said, "He'll just make it about him."
Sometimes we have to move a few mountains to make sure our kids can heal. It gets harder the longer that healing is put off.