More and more often I find myself in this kind of situation with BK1: We are speaking about something or I'm telling a story and I use a word that BK1 doesn't know. Today it was "Abenteuer", "Adventure".
Not long ago I would have explained the word, but recently I found the easiest way is to say it in English.
Tonight I noticed I was doing it and I thought 'I'm being lazy, I really should explain this in German!'
The two main points are, of course: 1. her English vocabulary has passed German vocabulary in size. I'm guessing it is bigger than French and Arabic vocabulary, too. When did that happen? And 2. she grew that vocabulary entirely outside our house, it is truly foreign to me. This is very strong evidence that both OPOL and MLAH work and work very well.
One thing: I have this idea in my head that at some point, I will start wondering how well I know my children. I always thought that and I probably placed that time somewhere around puberty. But now I'm wondering just how unknown my daughters will be given their first language is not mine. The time might come a lot earlier than I thought!
All I can do is keep OPOL alive. Let's hope the little German part inside their heads will always be my home...