I think you are talking about Malevolence Ability on Kirai? That is "After friendly Living or Undead model within 6 suffers damage for enemy attack. [...]".
Under this example. The Wall is Ht2, and if the friendly model is also ht2 and lower. Then the ability does not happen because the wall is blocking the aura.
If it was a ht3 model that suffered the damage. The summon model must be placed in LOS. Since the Ikiryo is Ht 3. You can summon her on the other side of a ht2 wall.