She is definitely not an astronomer. A lot of highly specialized and talented people who aren't astronomers or physicists are are critical to the success of big science projects.

Best to see her bio [1]:

I am a postdoctoral fellow with the Event Horizon Telescope and will be an Assistant Professor in the CMS department at Caltech beginning in 2019.

[1] https://people.csail.mit.edu/klbouman/

Astronomy is about computers to the same extent that computer science is about telescopes, as I think Dijkstra said.

Maybe not on paper, but she is definitely an astronomer.