In contrast to her husband, who has a rep as kind of a cold fish, Mrs. Gould is warm and beloved. If there's trouble, she's often on the spot to help out. For example, when war breaks out, she helps care for the wounded. Also, when the Viola girls lose their mother (on the eve of a huge potential conflict between Monterists and Ribiera supporters, no less), she takes the girls in and cares for them. We think of her as kind of like Marmee from Little Women.
Her friend, Doctor Monygham, worries about the fact that Mrs. Gould is always looking after other people, but no one appears to be looking after her. Though he seems to be a bit biased on the topic of Mrs. Gould (because he's nursing a pretty serious crush on her) he's got a point. Her husband has been almost entirely preoccupied with the mine and its operations/future since he took over his father's mining concession.
In fact, it seems like he's actually more married to the mine than her. Martin touches on the dynamic between the Goulds in a letter to his sister, in which he explains how the plan for him to escort the silver out of town came about:
"…she is such a good ally of mine. She seizes upon all my suggestions with a sure instinct that in the end they make for the safety of the Gould Concession. And he defers to her because he trusts her perhaps, but I fancy rather as if he wished to make up for some subtle wrong, for that sentimental unfaithfulness which surrenders her happiness, her life, to the seduction of an idea. The little woman has discovered that he lives for the mine rather than for her. […] The principal thing is that she has backed up my advice to get the silver out of the town, out of the country, at once, at any cost, at any risk. Don Carlos' mission is to preserve unstained the fair fame of his mine; Mrs. Gould's mission is to save him from the effects of that cold and overmastering passion, which she dreads more than if it were an infatuation for another woman." (II.7.72)
Martin basically nails it here: Mrs. Gould is totally committed to helping her husband, but she seems to feel she has to work around him (rather than with him) because of his blinding, borderline obsession with the mine. We know there are different kinds of adultery: there's physical cheating and there's emotional cheating, but this is the first time we've seen silver cheating.
So, unfortunately, Emilia's story isn't a terribly happy one; she gets more love and attention from acquaintances and friends than her husband, and she seems quite lonely at the end of the novel. Unhappy face.