I think the husband is only a shadow figure that supports the fact that she has two children and she doesn't need to look for a romantic relationship anymore. The title is "Mom Adventurer...", not "Wife Adventurer...", so the the series probably will focus in her motherly relation with her children (and maybe also with the younger members of her team). It is possible that some readers drop the series when they realize that the husband is not appearing (and not even required) in her adventures.