That is one problem, yes. Her retainer is here, of course, but she does not want to make things difficult for Linhardt or Bernadetta. Neither one of them has ever been particularly fond of combat. Even then, we outnumber her by far.

[Even the fact that he's thought all this out proves that she's right to be concerned. Their truce is a fragile thing, built only by the two of them agreeing that fighting here wouldn't solve their problems. Edelgard surely still intends to fight him once she's free, and though Dimitri doesn't want to slay her when he returns to his own time, he will if he must.]