The bigger question is whether she's connected to other recent green paint defacings at the Lincoln Memorial or on a statue outside the Smithsonian Institution, and possibly an event at a statue of Martin Luther in northwest Washington's Thomas Circle.
Initially police would not release her identity. In early reportage the AP mentioned a problem: (emphasis added):
The woman was arrested in the area of the cathedral shortly after the paint was found, Assistant D.C. Police Chief Peter Newsham said. Investigators were hoping to question her about the vandalism on the Mall, including at the Lincoln Memorial, but a language barrier delayed the interrogation, Newsham said.A name was finally released, perhaps explaining the language barrier:
D.C. police said Monday evening that they had charged Tian Jiamel, 58, whom they believe to be homeless, with one count of defacing property.It's strange to think that a homeless Asian woman, who can't speak English very well, would be traipsing all over the city slashing green paint on national monuments and statues. Stranger things have surely happened but there may also other possibilities, such as her not really being homeless; acting as a patsy for others; or having accomplices. Nothing has been permanently ruined so obviously it was about symbolism, assuming this wasn't the actions of someone who simply flipped their wig.
If symbolism was involved there has to be a motive, including whether the color green was used to signify something and/or whether the targets were chosen randomly or had significance. Since there were perhaps two Christian religious targets it's tempting to find some meaning there but for now it's better to wait and see where this goes.