Yesterday evening Lilia said "Das ist für Dich" ("that's for you"), and I did not even realise right away that she had used the accusative reflexive form properly! Hooray!
Before, she used to say "Das ist für Du" or - cunningly - "Das ist für Papa", so this is a big step towards speaking German properly.
Other things she mixes up most spectacularly: the other evening she wanted to put some object into another but failed. So, after some frantic struggling, she gave me the two parts and said "Papa, help!" (yes, in English). I said something like "Das ist aber auch schwierig..." ("that is hard...") and she started to explain, like so:
"Kann ich nicht. I got ... I got getried, aber ... I got getried, aber I cannot do it!"
Poor Lilia. Sounds like she is a bit confused sometimes.
Or, it could mean that she will always be able to use words and phrases from other languages as "fall-back" when she needs them, which I think is a brilliant ability!
And, thinking of it, Souad and I do it all the time. We often mix English words into our French conversation, mostly when we talk about things that we only started to speak about in England, or when the English word is short while the same thing in French would be half a sentence...