Convincing Polma to allow you safe passage through the room requires a DC 22 Ability check of either Persuasion, Intimidation, or Deception. Since a roll of such magnitude is very difficult in the early game, battle with Polma is difficult to avoid if you wish to proceed deeper into the Defiled Temple.
Like other ogres, she gets a +1 Strength bonus on Tactician difficulty, bringing her overall Strength to 21.
Act 1 Spoilers! This section reveals details about the story of Baldur's Gate 3.
If the player allows themselves to get put to sleep and captured by Gut, then fail to break free once captured (or don't bother to resist at all), Korrilla will kill both Gut and Polma.