You might want the direction of the fireballs to all be the same then? You would just created them a 3 points spaced out from the player. You could get these points like this...
The center point is obviously x,y.
The other two points are calculated out from the center like this... for example lets say you want to create them 30 pixels out from the center...
x1=lengthdir_x(30,image_angle);
y1=lengthdir_y(30,image_angle);
x2=lengthdir_x(-30,image_angle);
y2=lengthdir_y(-30,image_angle);
Create fireballs at those 3 points but all with the same direction and you should be good.
The direction might be the enemy's image_angle, or you could use something like direction=point_direction(x,y,player.x,player.y) to focus directly on him.