Model in Windows Phone using Sqlite

I am using in my app the sqlite db. In order to create the db and fill it with data I had to create a winForms project where I am also using sqlite. The same model in these two different cases is not working properly. What I have in winForms and works is that:

[Parents]
int ParentId
string LName
virtual List<Child> Children

[Child]
int ChildId
int ParentId
int Count

Exactly the same code doesn't work in Windows Phone. The list of children is always empty. Why is this happening?