Yes, obviously, but while you and I understand that aspect of things, it's surprisingly difficult to get people who don't fly very often (or ever) to understand it. And even more difficult when her parents (with whom she is in contact by email) aren't any more experienced at flying or living overseas in somebody else's house but are nonetheless altogether comfortable in advising her on exactly what she should do in said circumstances. It's much easier to counter her mother's "Pssshaw, never mind those idiotic American rules" if the French aviation security agency has similar rules. Matches seem like pretty innocuous items until you think about them.

She will be connecting at CDG to MRS, so the DGAC regs would be in effect there.