Emma glances at Hook, the reason they all went to purgatory. The reason Emma let her whole family come too, something she’s now finally questioning, because she let her son come. That face doesn’t scream “our love will find a way to save everyone,” but rather says “I came here for this person?”
Once Hook realised they were coming to save him, he insisted they leave him there. Once Emma told him otherwise (she is the saviour after all, as ill-deserving as some people may be) he agreed he was worth saving, and has spent 90% of his screen time insulting everyone else’s plans to get home, mocking Emma’s son, and generally just being unnecessary.
Snow: “We’ll face this monster together.”
Hearing “together,” Emma looks to Regina. She raises an eyebrow and gives a very slight smile. Emma’s eyes light up and, whilst her smile is slightly pessimistic given the circumstances, it’s an agreement, a connection. A “we may not survive, but we’ll be together regardless of what happens.”
Regina Mills is not in purgatory for Hook. She is there to support her family, her loved ones, regardless of what she thinks of what they are doing. She is the one who will continue to support Emma, and not judge her or make her an outcast for decisions of desperation. These women would sacrifice everything for each other’s lives, and each other’s happiness, because that is what they have become. SwanQueen is the overarching fairy tale to bring together all these other stories and characters (fairy tales or otherwise) and tie together this whole show, and I honestly do not understand the whole point of this show if that is not what brings it all together in the end.