Reselect your vertical path and make two copies in front using the Control-C > Control-F keyboard shortcut. Select these new paths one by one and place them as shown in the first image. Select all three vertical paths and simply Group them (Control-G). Make sure that your new group is selected and go to Effect > Distort & Transform > Transform. Check the Reflect Y box, enter "1" in the Copies box, drag the Move-Vertical slider at 17px and click OK. In the end things should look like in the second image. Move to the Layers panel, double-click on the group made in this step and rename it "vPaths".