IFirebaseClient client;

List<Student> listStudent = new List<Student>();
FirebaseResponse response = null;

public async void List()
{
    response = await client.GetTaskAsync("students");
    var result = response.Body;
    var data = JsonConvert.DeserializeObject<Dictionary<string,Student>>(result);

    foreach(var item in data)
    {
        Student student = item.Value;
        listStudent.Add(student);
    }

    dataGridStudents.ItemsSource = listStudent;
}