The source for this is Plutarch, which generally ain't great. He says that King Pyrrhus of Epirus (in his Pyrrhus 26ff) invaded the Peloponnese and assaulted Lakonia in 272 BCE, and that the Spartan king Areus I "was not at home, but in Crete, whither he was bringing military aid for the Gortynians." The Cretan city of Gortys was at war with Knossos at this time, though I can find no real information about this conflict or Sparta's role in it. It is not mentioned in the Cambridge Ancient History at all. From what Plutarch has to say, it seems we are to believe that a significant force of Spartans was on Crete, since Pyrrhus and his pet Spartan dissident Cleonymos falsely believed that the city was in serious danger due to the absence of the men. Plutarch continues:

When night had come, the Lacedaemonians at first took counsel to send their women off to Crete, but the women were opposed to this; and Archidamia came with a sword in her hand to the senators and upbraided them in behalf of the women for thinking it meet that they should live after Sparta had perished. 3 Next, it was decided to run a trench parallel with the camp of the enemy, and at either end of it to set their waggons, sinking them to the wheel-hubs in the ground, in order that, thus firmly planted, they might impede the advance of the elephants. When they began to carry out this project, there came to them the women and maidens, some of them in their robes, with tunics girt close, and others in their tunics only, to help the elderly men in the work. 4 The men who were going to do the fighting the women ordered to keep quiet, and assuming their share of the task they completed with their own hands a third of the trench.