Why did Artemis kill Andromache's mother?

In Greek mythology, Eëtion was the king of the Cilician Thebe. He is the father of Andromache, wife of Hector, and of seven sons, including Podes.

His wife is never named, but Andromache relates that she was captured in the same raid in which Eëtion was killed, and died of sickness in Troy following her release.

So, Artemis did not.