Lurking in the Stata listserv is a neat little graphics trick that might assist some. The desired graphical objective includes: "How do I combine both [normal curves], so that the normal curves appear on the same graph rather than one by one. Also, please suggest how to make one 'solid' and other 'dashed' with some legend."
Commenters, using Stata's standard "training" dataset ("sysuse auto"), walk through the necessary coding. (Warning: As the comments make clear, getting the coding to run took a few iterations and some corrections to earlier coding suggestions.)