It has to be portable because she is a two-house kid? Some of the Maruzen Kenmores are aluminum body and a little easier for me to sling around than I had expected. And I am small and short.
I learned on a Singer Touch & Sew 600E and yes I spent a lot of time playing with the cams and built in cam stacks. (And making and cutting out thread jams, because...Touch & Sew.)
But then you have this wealth of experience and machines that was not there when we were growing up. Maybe give her the Kenmore 1303 now (and talk someone else into giving her wheeled luggage for a case, too) and say she still can use another if she needs to do something that machine cannot. Maybe she will claim the simple machine as her own. Maybe she will fall in love with cams and you can agree to 'trade' machines later and find her one with cams. Or she picks out one in all blue, or a hand crank, or whatever.