If one is a Picard / Crusher fan you can fudge the details a bit to support the Nexus vision being indirectly about her.
The Nexus vision is pulled entirely from Picard's mind, so while his deepest wish would be to settle down and form a family with Beverly, his loyalty to his dead friend Jack Crusher is still so powerful that it prevents him from even fantasizing about it in his initial vision. So instead his mind pulls a strikingly Crusher-like Ensign Brooks (another Starfleet widow with red hair serving on the Enterprise) out of his memory as a temporary placeholder until he's ready to fully confront his feelings for Beverly.
Eventually if Picard had remained the vision would be about him and Beverly and their kids having Christmas dinner with Rene. Maybe Picard would even have patched up his relationship with his brother Robert enough (again) to invite him back from the dead to Christmas dinner too, along with Robert's wife. So they all could be one happy family.
Even Kirk's Nexus vision underwent rough drafts like this, where he was first bringing Antonia breakfast in bed and then later went back to the day that they first met. Maybe it was just a part of an arc he was undergoing in his mind that would eventually take him through several past loves and all the way back to marrying Carol Marcus and raising David. Maybe it's a way of visualizing your greatest pain or regret, like a supercharged Sybok, but then reliving it in a different way until you find what makes you most content.