What would you do if your Sergeant didn't know how to load a magazine?

Looks like she needs a bit of extra training. I was a combat Engr officer in RVN and we has a 20 minute class in the proper way to fill sandbags it include one to three people to fill them a 1.5 hour practical exercise in filling the bags. One could do that for loading ammo mags also. Lesson plan and everything required for extra training. The IG even liked the training when he came to check out our abusing the troops. Plan was adopted Corps wide.

When the WACs where transitioned into the branches we encountered a number of female soldiers who did not know how to perform basic weapons functions. They did not qualify on weapons. Lt Knutson was one of those. We checked out a 16 and taught her. On the weekend we went an informal range and took her through an intensive shooting session over two days. She qualified expert and became a hard core shooter.

It is obvious that the SGT had missed a part of her training. Should not be punitive but should receive remedial training.

I've been out and procedures and even weapons have changed a lot since then. I know not all mos's get as much range time and field training as others. After my first enlistment as a medic in a rifle platoon, when I re-upped I was sent to nursing school. When I got posted to a hospital afterwards I would be sent to the range with Doctors, nurses and chaplains and the like who basically saw their weapons once a year when they qualified. As a grunt medic I got to shoot almost everything in the inventory ( couldn't open a range then without a medic on sight and after all the qualifying was done, the range detail would often get to shoot up some of the leftover ammo). I had a blast teaching Doc's and preachers to shoot and so did they. Give this Sgt. A break she may not be Rambo but when you're in the OR with your life hanging by a thread she might be the one who saves you.

No soldier on any firing line I was responsible for would be that ignorant. When I first got my warrant, I was put in charge of our unit's weapons training. Got a few young privates that had just enlisted and got their uniforms, had not even been to basic yet Got out the "Soldier's Handbook" and made them read it. After they had told me they had finished it, I started to question them. Then, we went to the arms room and and I had them demonstrate their familiarity with the M-16's. Every one of them checked out fine. One in particular, was outstanding. Even had him conducting refresher classes on maintenance of their individual weapons for the rest of the company. (Last I saw, he had transferred to an ANG infantry unit, and was, by then, an SSG.) As far as the "female issue," forget it. Every female in our unit was expected to pull their own weight. You loaded your own magazines, regardless of who you were, from the C.O. on down.

I was a reservist in Med Corps. We were constantly begging for ammo. Big Army didn't think we needed it so we got little to no range training. I had it in Basic but that's it. When I got Activated I let them know up front that I was willing but inexperienced.

show him/ her how... why make a big deal out of it, nobodies perfect

I would teach her.

When you only have two days of training a month and two and a half weeks of camp to train... Then take away time for all the mandatory bs, which strangely involves little or nothing to do with soldiering in a real sense, more time for other admin stuff, more time for various maintenance tasks... Very soon your training time has been significantly reduced. My experience as a National Guard infantryman will serve nicely to demonstrate the problem. When I started with my unit we were equipped with M113 APC’s. Not much to them, drive em, wash em, check oil and tracks, put em away til next time. Training time was minimally impacted by requirements of the vehicle. Then we were slated to receive the Bradley. Very exciting! I read the gunnery manual cover to cover. I learned one major thing, we didn’t have enough training time in our annual training time to be able to ever actually qualify to standard. And that was before all the time was lost to the aforementioned non Mos specific stuff. The Bradley requirements greatly increased PMCS time before and after use. To be able to go to gunnery (which goes all the way to table twelve but under conditions where deployments were not imminent we only went to table eight) all SM’s have to have qualified on their personal weapons within three months prior to the actual gunnery training. If we were qualifying on weekends then we were generally capable of completing one table per weekend but one table for a battalion took two weekends because we were self supporting so gunnery takes six months of training for a battalion, not including makeup for crews that fail a table first time around on a specific weekend and have to perform that table again another weekend. Snowballs. This is only one issue that we faced with our limited training time. I will say that when deployed on real world stuff, Bosnia and Iraq that my company , A 1/120 INF, were a very well trained and fully capable bunch of guys and I believe it is safe to say the same for the rest of the brigade, 30th Infantry Brigade (HVY)(SEP) “OLD HICKORY”. What made the difference between “not enough time” and being actually qualified and competent? The soldiers. Guard soldiers are mainly in combat units and have a care and pride in what they are doing that is immense, their willingness to go above and beyond is phenomenal. As always there were exceptions, our leadership challenges! Leadership was another entirely different challenge than AD. Much work is conducted while in an unpaid status, troops callled in to conduct extra training and admin on their own time after a full days work on a civilian job. Leaders have to prepare training, evaluations etc between drills. Visit soldiers with problems, including those of their civilian life that affect their military life, that’s one that is not nearly as big a problem for AD leaders. These are not complaints, this was part of the challenge of this type of service and I relished it. I found it far more satisfying than my active duty time with the British Army and the USMC.
I hope this illustrates the problem faced by reserve soldiers in staying competent, currrent and ready. It’s a great challenge and not for everybody! I miss it more than I ever thought I would.

She would be off the range

If she needed a refresher on a common task, that's one thing; in the case of magazine loading it be 2 minutes, tops, to be shown how to do it. She might have gotten a bit of grief for forgetting, but that's why we train. She should've just asked for a quick refresher and drove on.
But getting on the firing line and then confessing you forgot? Well, you deserve the embarrassment, (at the very minimum), that's coming.