Grandaddy,
I admire your schedule, I think I will try to work up to six days a week also. I think you are right about the popularity of Meridians and their affordability. I have of course seen pricier trikes and beautiful, quality recumbents but they are not in the budget for me right now, fortunately until the spoke issue, the Meridian was perfect for my needs, and will be perfect again as soon as the new wheel arrives. Lots of seniors like me are on fixed incomes and the Meridian is affordable and fun, and gets them out and riding.
Everyone is different, and if your SIL does not want to be seen on a trike then that's they way she feels. I don't worry too much about my Meridian and appearances, it is good exercise, I stop and chat with people, and it has been a positive experience for me.