If she has a disorder, the red flags will come up over time. The severity of it though will effect how far apart those flags are.
The high functioning ones you may not notice because of the longer time between flags and your own building investment in her, but your gut may tell you something is off with her.
Low functioning ones have more frequent flags closer together and are easier to spot.
Check for an abnormal childhood or family situation paying particular attention to her relationship with both her parents if you want to be proactive.
Mine actually independently told me about hers, but she dripped it out with 3 to 4 months between her revelations, and she had plenty of them. During that time, I was getting sucked in deeper and deeper.
Keep your eyes open and know the symptoms if you suspect it and proceed as normal unless flags start stacking up.