The cake is eaten and my cousin and his wife really liked it. :) Even their little one year old got a taste for pannacotta. :) 
It got almost as I had hoped. Good that the blueberry layer were thicker than the chocolate pannacotta. The fresh blueberries gave a nice texture to the creaminess from the pannacotta. All in all a good result. 
I had a great time, too. Playing with the oldest little boy and got sweet smiles from the little one year old. We will see each other more now, before they return home to Germany in the end of the month. I'm so relieved that my energy is rising to a (for me) more normal level. I always need to rest after being social, but that's just how it is.