Dear Amos,
It all depends which part of Croatia she comes from, but there is something I know everybody likes: Beef pastissada with gnocchi- http://cookeatshare.com/recipes/beef-pastissada-with-gnocchi-603658
Also, you can find in my blog some of the usual Croatian food: http://lakakuharica.blogspot.com/search/label/Croatian%20everyday%20cuisine. Look for the tags on the left side of my posts. I hope you will be able to find something that would be nice and easy to prepare.
Lots of luck with you wonderful idea. You are a really great friend:)

One of my dearest friends is Rose (Ruza), a Croatian girl who is simply one of the best bakers in the world. So I am delighted to connect with you on C-E-S! Best wishes, Amos