Unless she 100% knew he would survive going into that forest, she is a psycho-bitch. Her actions in this chapter are irredeemably evil, why doe not matter, all that matters is that she did.
Just trying to let people who were looking forward to a revenge story know that they will be let down by this series. You are right that from the perspective of the summoned people the princess is an evil psycho-bitch. She fully intends to use them as slaves and kill them if they don't obey her. But the author gives her a redemption arc thing because it turns out she genuinely cares about the people of her kingdom and was desperate to summon heroes to protect them from some big threat. She also only treats the summoned people like trash due to a dumb misunderstanding. In the end the MC forgives her and she becomes part of his harem.