Unfortunately, she may need to perform a regular maintenance regime before and after long rides; anti-inflammatory med before the ride, ice over the affected area afterward 20 minutes on/20 minutes off/repeat, heat before bed, and heat on the off day.

Measure the Q to see if there is a gross disparity between sides. Most of us tend to favor one side of the saddle in any case, but she may be compensating for a mechanical unevenness. I have an older model crank and bottom bracket with a difference between sides that I reduced by chilling the spindle (placed the bike outside in the cold), heating the wide side arm, applying thin lube film to the taper, and quickly mounting the hot arm. You can't do that specifically with yours, it was just sharing. I also have pedals with adjustable Q & tilt (Look CW-7). I'm aware of others who have no problem with uneven cranks, but I'm experiencing a change in comfort from bringing pedal Q to near even from frame center, plus increasing overall Q from narrow widths I preferred 12 years ago. In the past the saddle nose angled off center to keep one thigh from rubbing, now it's straight. BTW, I'm more conscious of sitting centered which may be more important than manipulating Q.

Speaking of saddles, their shape and placement is probably more affecting than Q.