This really sucks for her, but...
My wife and I went to the 9/11 memorial for the first time this past weekend. I guess I shouldn't have been surprised by the security, but I was. Access to the memorial is similar to going through airport security.
You don't just show up. You have to get tickets online and show up at a particular time. You then stand in line for a while waiting for security. Before security there is a big sign with icons for no knives, guns, mace, or tasers. At security, you go through metal detectors and wands, and your bags get x-rayed. It looks just like an airport setup. You have plenty of time to get out of line and leave. Even if I had a CCW permit in NY, no way would I carry there having seen this setup. The memorial itself is in a sterile area beyond security, and there is a significant police and security presence.
In her defense, I'm sure she thought it was normal to ask for a firearms check. But surely she checked carry laws for NY and made a decision to carry anyway prior to traveling? Perhaps she got there and was half way through the line, when she realized "oh shit". Yes, it's completely BS that New York is like this. But damn...
The memorial is beautiful by the way. Truly sobering and respectful. It's a shame that it's like Fort Knox getting in there to see it. I hope that they dispense with the TSA-like crap once all the construction around the memorial is done. But this is NY we're talking about.