You are right about that lise would never be able to understand his pain but she has already scene what will happen afterward when he was able to avenge is late mother and sister. He went insane after losing his brother. So she just doesn't want linden to go through that once again.
she's not asking him to forgive them but to spare them. like the comment above said even after he takes his revenge he went insane, he didn't get any happier.
Her entire family was killed aswell as herself but she forgave him somehow
i really dont like lise's action rn, being reincarted doesnt mean that it is your responsibility to intersect every tragedy, also i hate the way lise's being so shallow rn, you cant ask someone to forgive the literal muderers of their mom and sister, i know she has linden's best interest at heart but please dont pretend like you know the pain and like just be like that idontknowwhyimangry