i watched it and i thought it was pretty balanced. on my "EPIC" journey to Paris (which was epic enough for me) you do have those times when you lose heart. this time, i went not having done any training because of my broken collar bone and on the 2nd day there was a point when i just wanted to throw the towel in, and get on the van. it was 30 degrees heat and i was just like "why the hell am i here when i should have pulled out because of my lack of training/injury" but i didn't and all the pain is worth it just for the end result.
my point being when you are on these rides you see people as they really are, at their lowest, at their funniest, at their moaniest, and at their highest. this guy did moan sometimes but i totally sympathised, but there were times when he was like WOW THERE IS NO OTHER PLACE I'D RATHER BE.
i reckon the best thing you can do is get her on a 100 miler. let her whinge all the way and then see the elation she feels at the end. then she will truly understand you have to experience the lows to feel the highs.