Depends on what color you play. For shadow there is
life weaving
Unholy power/hero
infect/frenetic
nature:
typical heal spells(surge of light, ray of light, equilibrium, regrowth)
cc spells(pink, root)
damage: thunderstorm
damage reduction(for friendly units): Revenge
frost:
freeze spells
damage reduction spells( Area ice shield, ward of the north)
fire: damage spells( wildfire, sandstorm, lava field, meteor)
unity(to save her units if need be)
There are many more cards in those categories that I’ve probably missed, mainly spell or buildings but the one I listed are good for almost all situations.
Have fun showing your wife the game