The only reason I see it would be smart to do PPL in a MEP if the student owned the aircraft and it would be cheaper to fly his own twin than rent a single-engine trainer - if such aircraft even exists, which I highly doubt
I flew such an owner in a Seneca five twin for a few years. As most was SP I taught him how to fly the aircraft until the point that he used to fly the whole route from the right seat.
The owner started training for an FAA PPL in the aircraft after I left although I believe he did part in a single.
If the missues is worried about singles why not a Cirrus then you can tell her it has its own parachute system to lower you all safely to the ground in event of you having a heart attack
Pace