They found it after they went through her backpack.
Extra info: if you declare everything, even if it's something that's definitely not allowed, you will not get into any trouble. I'm talking about food and stuff not drugs or guns. They just don't want people to not be declaring things that then slip through without inspection. That's why there's a heavy fine if they have to "catch" you. A lot of things are okay'd to be brought in after inspection.
I hate it when they quote a time but no timezone. 10.37PM according to who?