Welcome to the forum, has your friend been diagnosed by a professional with PTSD and if so for how long and is she receiving treatment for it? Also there is a fair difference between (for example) a road traffic incident, adult rape and long term childhood abuse. For example someone who'd had a very bad car crash might still have trust issues, but these would be less likely to be the result of being proved not to trust anyone and possibly not physical, where as someone who'd been raped would have fear both in trusting people emotionally, physically and sexually as would a child abuse survivor, however there trust issues maybe deeper and have additional issues with dissociation and maybe personality disorders. So if you know this might give us some more information to be able to help you with, although it varies greatly from individual to individual.
A lot of us with PTSD can be overly critical of others as a defense mechanism to not allow other peoples behaviours to be harmful to us, to test others to make sure that they are "safe" to us and just like most people we can be cranky but the PTSD can rev it up a notch. However not knowing your friend or anything about her, it is of course possible that she could be jealous.
Why is it that you want to know if it's jealousy or not, is it because this behaviour is having a negative influence and perhaps ruining your friendship, because you want to know if she might be interested in you as more than a friend or something else. Sorry for the interrogation, it's just this is very complex and we don't have much to work with to help you or provide some answers.