Excuse the variable names, but here is a code snippet of dynamically adding items to a stack panel
StackPanel split = new StackPanel();
TextBlock expected = new TextBlock();
expected.Text = "Expected Final Bonus";
TextBlock meh = new TextBlock();
meh.Text = Math.Round(((QuoteData)results.First()).ExpectedBonus * 100, 2) + "%";
split.Children.Add(expected);
split.Children.Add(meh);
TextBlock disc = new TextBlock();
disc.Text = "Discretionary Percentage";
TextBlock number = new TextBlock();
number.Text = Math.Round(((QuoteData)results.First()).Discretionary * 100, 2) + "%";
split.Children.Add(disc);
split.Children.Add(number);
Here you can see that I also created the stack panel dynamically, however, you can also create it using XAML.
Something like this should work:
<StackPanel Grid.Row="3" Grid.Column="1" Name="split" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Width="Auto">