These days, I often find myself running for a pen and paper. Any pen and (virtually) any paper will do because the main thing is to write down as quickly as possible what my daughter (3½) just said.
Why? Because half a minute later I will only remember what she said, but not how she said it.
You’ll tell me that’s a problem every parent has who wants to record their offspring’s quotes. But when you’re on the hunt for bilingual quotes, it’s especially important to be accurate, as the way your child uses and mixes (or not) her languages will evolve over time.
Here are some recent examples to illustrate what I mean:

During breakfast: „Je vais couper ein bisschen was ab.“

Playing alone and talking to herself and her toys: „Macht nichts. On kann nochmal machen.“

She says something and I answer, but she was talking to Daddy: „Ich hab doch nicht parlé mit du, ich hab parlé mit Papa.“

(French words in italics.)