If she doesn't like PDA, it is more likely that she will feel more respected if you accept her wishes. I do like holding hands and touching fingertips though. It is completely possible that even that is too much for your girlfriend. If you can talk without blaming her or hinting that you really would like PDA, I think it could be interesting to talk about what you both like, what not, and maybe even why, simply as part of getting to know each other better.
Respecting her stance on PDA means in this context not trying to "fix her". There is no default here, just human beings with different preferences.
The only abnormal finding may be a distinctive type of murmur (noise heard with a stethoscope).
The ductus arteriosus is a hole that allows the blood to skip the circulation to the lungs.
However, when the baby is born, the blood must receive oxygen in the lungs and this hole is supposed to close.