Elma deals with these potshots by completely ignoring them -- in fact, she makes herself a more obvious target by jumping back down to the ground, away from all cover. The bullets that impact her simply get absorbed and broken down by nanomachines (son!), leaving her none the worse for wear.

In turn, that lets her focus on the guard aiming at Link, rattling bullets off the side of the truck to keep him from drawing a bead.