Self explanatory title.  We currently have 2 opportunities to save her from death, one of which puts our MC at the risk of dying, and yet we can't convince her into marriage?

Remember, she is devoted to Ana. The MC marries Ana to prevent the guilds from killing her. At this point, only one marriage is allowed. Perhaps in the future....

If that's the case then at least let us marry Aire if Ana is no longer in the picture, similar to how the MC can choose between Lira and Hele.