I haven't played the games in forever and my memory when it comes to gaming is BAD.

She was carrying around her Dive HM and accidentally died/fainted, which cleared out her items.  She cant figure out how to get another one and she needs it to progress.

She's kinda upset and keeps asking me if she should reset the game from the beginning (she accidentally saved).    There are other options, right?

This is a bit cheap, but look online for a Wondermail Generator...or ask some people to send you a code for the item.

The Wondermail Generator...lets you generate...missions (whatever kind) and rewards of whatever you want.