Figure.7 shows the polylines drawn for the lower body.
The front and back polylines need to now be mirrored just as you did for the upper body. In Figure.8 you will see the newly mirrored polylines along with the old ones.
The mirrored polylines are in yellow to separate them from the father splines. You can now Loft as you did on the upper torso. Figure.9 shows the output of the loft.
For the legs we will use the same method as before. Figure.10 shows the splines in different layers only to show the different polylines.