Depends, you can solder on both sides of a 2+ layer board. Some have this fear of soldering on anything but the bottom, but there are exposed leads on both sides. I regularly solder both sides, especially when there's a large copper area that needs extra heat - sometimes two irons are used, but that's dangerous and can destroy your board easily and I wouldn't suggest it unless You Know What You Are Doing Thank You Very Much. That's not a board you'd use that kind of iron on, however. That looks like one of those old ratshack style irons with the thread-in tip. Those are fine for old radios, but I'd never bring one of those near any modern board, especially with a tip that is the equivalent of trying to put a decorative rock in your garden and ordering a mountain's worth of rock for the job. TBH, you'd not be repairing that board anyway. Motherboards are commodity devices, and unless it's a case of infant mortality, the board would be discarded when it's life was over. TL;DR, she loses on all counts.