Can you get diabetes from a big impression?

My aunt has Type I diabetes since she was 25..she is now 60. She says that she became diabetes after her 5 year old daughter was runned over by a truck. My aunt presenced the accident and she tought that her daughter was killed...Fortunately, her daughter was unharmed, just a few scratches..but my aunt ended up in the hospital and she said she got diabetes since then...I find it hard to believe, maybe she had it already and she was diagnosed at that time...What do you think?