Your GF fought with a very brave unit. They'd had almost no military training and no experience of battle before being sent up Spion Kop as reinforcements.
Here's the account of Maj JF Shaw, who commanded the ILI at Spion Kop:
It must have been about 11:0 AM that a staff officer suddenly appeared in our front, as we stood awaiting orders.
He had lost his helmet, and was bleeding from a slight wound in the head.
In his hand he held a slip of paper, and called for our C.O. at this moment, there were only three companies of us present, the other five companies under the colonel having been detached somewhere a short time before. So the captain of "C" company, as the senior officer present, stepped forward.
"The orders are", went on the officer, as he handed Captain X – the paper "that the Imperial Light Infantry are to reinforce the Dorsets" and he proceeded to indicate the general direction of advance adding that we should find the Dorset battalion in position at the summit of the hills on the right. Now this movement (as subsequently transpired) was about the very worst that could have been ordered under the circumstances! However, in obedience to orders, we commenced the laborious ascent of the mountain, which took a considerable time, owing to the steepness and the constant necessity for halting to take cover behind a huge bolder from the heavy fire. However, the top was gained at last, and here, a most deplorable situation came to light.
Five British battalions were wedged into a small and narrow plateau, of a frontage and depth barely big enough to hold one battalion! And again, the position held by the forming line was not even the actual summit (as supposed), since the ground sloped gently upwards for about 60 yards in our front terminating in a line of boulders, which was held by the Boer front line and greatly to their advantage, being quite concealed from view, or fire, or our firing line!
In addition to the heavy and effective rifle firing from the front, at short range our position was being successfully shelled by the Boers guns, posted on both flanks, which maintained a heavy and murderous arms & enfilade fire, and also, a howitzer in position on the lower slopes of the enemy side of the hill, was making excellent practice.
Meanwhile, our own artillery, as already explained, were adding to the troubles by bursting their shells mostly over us in preference to the enemy.
The arrival of still more reinforcements, in the form of the other five companies G.LG, & of Thorneycroft's Mounted Infantry (on foot), only tended to still further swell the congestion at the already overcrowded plateau.
The men lay in the hastily improvised so called trenches literally packed like sardines in a box.
For my part, all I could do was to lie down flat as possible clear behind the firing line, and hope for the best.
Personally, I never once fired my rifle firstly because I could not see anything to fire at, and secondly, because to have done so would have been dangerous to our men in my immediate front.