It's not a bother. They're one of the fear settings, I don't remember the name, but it gives enemies a chance to spawn revenants (the green orbs) when they die. If you don't pick the revenant up, the enemy will respawn at full health with armour if it had.
If she does it as she is impervious the shield bubble sticks on her for a bit. I've always assumed she goes the furthest from you and it usually works but sometimes it doesn't. Mostly I just guess and hope it works out.
