YOU SAID:

I decided to eat my sister at home today. Nobody noticed, since I put on so much tomato sauce on her that she looked like a lump of play dough

INTO JAPANESE

今日は妹を家で食べることにしました。私は彼女にあまりにも多くのトマトソースをかけたので、誰も気づかなかったので、彼女は遊びの生地の塊のように見えました

BACK INTO ENGLISH

Today I decided to eat my sister at home. I poured so much tomato sauce on her that no one noticed, so she looked like a chunk of dough for play