setting region of a user control that has a graphicspath with varying outline width

I have a user control1 hosting user control2. User Control2 outline is drawn with different Pen width.

I need to set the region of user control1 so that the user control2 shape is maintained irrespective of its outline width.

User Control2 path data and its outline width value are available as properties to be accessible by User Control1.

How can I do that?

Thanks