Try this :
<Border BorderThickness="5" BorderBrush="#FF30333A" Width="{Binding Width}" background="#FF1C2125" Height="{Binding Height}">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Path Grid.Row="0" HorizontalAlignment="Left" Name="starPath" Fill="Gray" Data="M 9,0 L 7,6 L 0,6 L 6,11 L 4,17 L 9,12 L 14,17 L 12,11 L 18,6 L 11,6 L 9,0"/>
<TextBloc Grid.Row="1" Text="2" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" VerticalContentAlignment="Center" HorizontalContentAlignment="Center" FontSize="20"/>
</Grid>
</Border>
So ? does it works ?