The officer who pulled the OP over did not arrest her, did not seize the vaping equipment, and did nothing other than his job. When he advised her about not vaping and driving, it was most likely a courtesy (like trying to be nice, hello) for her to avoid getting pulled over again.
Nothing I've said will change any minds who have personal axes to grind against the police.
I'm glad the OP has (from what I read) recognized an opportunity instead of a victim-status moment. The officer violated nothing, based on this account of the story from the OP. He did his job...what a concept for some people! LOL.
When the cop pulled her over he was doing his job. He saw something that he believed to be possible illegal activity and he wouldn't have been doing his job if he hadn't pulled her over to check it out.
Once she showed him the device and explained, there was no reason to push this further. He had no probable cause to search her and this is exactly why he asked if he could.
After determining that she wasn't doing anything illegal, and wasn't posing any kind of threat on the road or otherwise, he should have told her to have a nice day and drive carefully.
Although he didn't violate her rights, because she did give her consent, there was no need for him to push her for a search in the first place. Cops will do this, because many people are afraid to say no. Many people don't know their rights or are afraid to stand up for them, and the bully cops count on this.
His job was done after he pulled her over and determined she was vaping and not doing anything illegal. If he was truly "just doing his job" he would have let her go at that.
I have the utmost respect for the police that are in it for the right reasons, but unfortunately many are in it for the power and control. These guys cause a lot of trouble not only for civilians but for there fellow officers. And once they are in, it is often hard to get rid of them. My uncle is a retired officer and has worked with many of these jerks over the years. There's one in particular that they've been trying to fire for years but every time she threatens sexual harassment suits.
Standing up for your rights is the only way to fight back. The "good cops" generally won't put you in a postilion where this is necessary, and if you don't stand up for your rights when you encounter a bully police officer, these officers will never be held responsible for their actions.