Do 'native' speakers of English understand it when they read it? I said what I said and I repeat it again - one can only have one native language whether you like it or not. Never did I say that one's native language is the one you're most fluent in - you're putting words into my mouth, joysof, shame on you for not understanding the language you're supposed to be a native speaker of. In the case of your friend - German is not her native language at all, no matter how long she has spoken it, if, coming to, she babbles in English. (I wonder what language she screams in when she comes - play your cards well and you may find out I've been right all along, matey) . Following you logic you can say that Udmurt is my native language just because I was unfortunate to be forced to speak it in my childhood... Like hell it's my native language - I've forgotten all of it by now and good riddance to old rubbish, I would never have used it anyway, it would only have used up my braincells.
Like I said again - the pain/shock test dots all the i's (расставляет все точки над ё, as we say), no surprise Colonel Isaev aka Stirlitz said to whatsername not to give birth in Germany for she would have cried out in Russian when in labour.
BTW, aren't you the one who once claimed to have two native languages - English and French? Ever planning to come to St Pete? We could test you and the Dutch kid... You know, joysof, it's sooo easy to babble when one's sitting thousands of miles away... Believe me, face to face you wouldn't be so cocky.