I have a Sister who is average intelligence but she is very good at making people think she knows a lot. It only takes maybe 10 minutes for intelligent people to see through her but some never do.
I also remember a guy who could fake being a great baseball player but it only took a few minutes to figure out that he was not.
When we started practice for our Summer softball team, he told us he had been signed to a pro contract but for some reason, he could not take it.
Actually for the first play or two, he looked like he was good. As the saying goes, he had all the right moves. Unfortunately for him it only took 3 or 4 minutes to realize that he looked good while making errors.
He had a letter jacket which in the middle of the letter were the small letters, MGR. We all knew that meant “manager” but he told everyone it stood for “most games recorded”.
It would have been funny if he wasn’t such a sad sack.
I would bet your Sister uses similar phrases about specific issues and topics that she has mastered.