Our TG Caption

You don't really have any real grudge against your (now) half mother and little sister. But you feel as you can't just let witnesses go; also you need a place to stay. You remember all the times your little sister complained about not being able to do grown up things, and all the times your mother reminisced about her younger days. You say a couple words with your twin, and you agree that you should merge them into one but that they shouldn't keep any of their memories. Thus you scramble their memories as you merge them, letting their new form keep all the wisdom and skills your mother accumulated over the years without being able to tell when or were she learnt them. You let their combined form be as smart as both of them combined unlike your brother whom you made exceptionally dumb. You and your twin move their body inside and lay it on the couch; you decide on what to tell her when she wakes up. A couple minutes later she's up.