Ok its late so not think very clear, but does any range characters have Force Weapon? or are they all melee?
Also this character does it have to be an existing Force Power?
My version of her character had this,
Defensive Web (Force 2; If any ally (including this character) should take Damage from a ranged attack with 4 squares, this character can make a save of 16, if successful then all damage and effects from that attack is prevented)
This was the final character
She runs out of force points very fast. just an idea but fully understand if you require it to be an established ability