There is an alternate way to do it in a program like Photoshop that might be a little easier, at least to get the line started, but you have to feed the path information to an Illustrator file.
@jbmanning5 wrote it up here:
Photoshop to Illustrator / Quick Outlines and Vectors of Photoshop Paths
Since I’ve got both of those, I did a quick rough outline around the girls for you and saved it as an SVG file. If you want to cut out the area between the legs, you can practice with the manual pen tool in that area. Otherwise doing a manual trace on something like this would take a very long time.
Feel free to tweak it with the Inkscape tools.
_girls.zip (106.4 KB)
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