the singlespeed "elitism" is starting to take hold, how do i avoid it?

i went out on a quick 3 mile family ride down Long Sands on York Beach, Me, my mother and myself, she was riding her rigid Haro Vector M1 MTB with the high-rise "beach bars", and i was riding my old Fila Taos

i haven't fully converted the Fila over to SS yet (my mechanic at my LBS says i should keep it as close to stock as possible as it's a potential collectors bike...)

whatever...

it's a decent bike, yes, but it's nothing special, at the moment i've decided to leave it in 32/18 (i think) on the chainring and just not shift it, no, it's not a *true* singlespeed, as it still has the deraileurs and cassette, but in the month or so i've been riding it, i've never taken it out of that gearing, so it's a "Pseudo-SS" for now

anyway...

i was happily cruising along at around 10-12 MPH, keeping up a nice cadence and rythym, when i hear the clunk and rattle of gears behind me, Mom was trying to shift up to the big front chainring and the front der. was being obstinate and fighting her...

my first instinct was to snicker at the back of my mind, heh, wonky deraileur giving mom a hard time, my P-SS is churning away, completely hassle free

then i thought "y'know, if Mom converted her bike to SS, she wouldn't have that problem...

while loading the bikes back on the racks, i asked her...

having trouble with the front deraileur again?
yes, it didn't want to shift up to the third ring
why don't you just keep it in one gear, i rode the whole way in one gear, never shifted once
well i normally do keep it in one gear, i just wanted to go up to the third ring to flex my legs more
(she's fighting bursitis on her knees right now, so climbing hills is difficult and painful for her, she's trying to take it easy)

i'm also trying to make her bike more comfortable for her riding on roads, she has never taken it off road, so her Kenda semi-knobbies are holding her back with increased rolling resistance, i keep reccomending she put slicks on it, as she never takes it off road, but so far she's been resistant to the idea as her tires are "just fine", however, today she was looking at my bike and remarked how "i can see how the slicks would be better on the road"

maybe she's finally listening...

and yes, i am trying to get her to try light woods trails/fire roads, but she needs to let her knee heal first....