Get a Canon EOS Rebel T6 EF-S 18-55mm IS II Kit. About $450.00 new.
Gets her into an incredible system that any EF or EFs lens ever made will fit. But beyond that that is unique to Canon these lenses also will work 100% perfectly with her new camera even if the lens is one of earliest ones ever made. It will be perfectly compatible and absolutely no loss of any function. She can't beat that with any other system and she can grow and do any type of photography from high power sports with an EOS 1DX MII to the highest resolution FF DSLR made in the 5DSR. The T6 is incredible in it's own right and is a part of a full system she can infinitely grow into including mirrorless.

I'd guess that 98 out of 100 "camera problems" are no fault at all of the camera or lens... but are due to the user doing something wrong.

If you could post them, it would be very helpful to see one or more of the "faulty" images with EXIF still attached.

You mention 20 second exposures and that should always cause Long Exposure Noise Reduction to operate when it's set to "Auto" (or "Enabled"). Set to that, LENR should activate with any exposure of 1 second or longer.

Are you aware how LENR works? It's actually two "exposures" of the same length, one right after the other. The first is the "usual" exposure where the shutter opens and an image is recorded. The second that immediately follows is a "blank" that the camera does with the shutter closed, which it then uses to detect noise, which is then "subtracted" from the first image. So a 20 second exposure will take at least 40 seconds, for example. any exposure with LENR applied will take twice as long as it's setting on the camera.

That explains why your "exposures" were taking so much longer than the other people... they probably didn't have LENR enabled.(I would probably turn it off for star field shots, too.... but you should ask them.)

Here's the tricky part... If you forget what's happening and cancel the second "shutter closed" exposure for any reason (such as by turning off the camera), the camera will dispose of BOTH the LENR and the original image!

If you try to "light paint" during the LENR "blank" shot with the shutter closed, your efforts won't be recorded.

Generally speaking, the 6D is a very low noise/high ISO capable camera. One of the best. Should have been able to shoot without LENR, at at 6400.You might give it a try.

The main reason many night shooters use f/2.8 lenses is not necessarily that they use the lens wide open... In fact they may stop the lens down to an optimal f-stop for best edge-to-edge sharpness with the particular lens they're using. (You should test your lens to see what it's optimal f-stop is.)

Many users might choose an f/2.8 (or faster) lens for a brighter viewfinder. But with DSLRs, Live View and Exposure Simulation might be a good substitute.

I don't think you have any idea of how shocked some of us were to read your question; it was basic, plain and simple - and remarkably wise and thought-provoking. As I began to write an answer, having used the term stops for 60+ years, I suddenly realized that it wasn't one of the sequence of numbers we use to explain an exposure variable. As I stop (pun not intended) and think about it, I realize that a stop is not just the size of the aperture; a stop is one of those ubiquitous terms we throw around about apertures, shutter speed, ISO, filter density, etc., without giving any thought to the complexities we are discussing. It has a myriad of definitions, meanings and purposes. When you read your book, you will know what the word generally means, but you will also learn the context of its use - and that will lead you to a better understanding of photography. I won't try to answer your questions; the answer is more meaningful than many of us understand. Thank you for your question and for having the courage to ask it. Don't let smarmy remarks and jokes lead you to think it was not a wise question.

And, by the way, the next time a sales representative asks you a question you don't understand, ask him/her to explain the question. You don't have to believe them; just listen to their sputtering inane explanation - because by that time you will know the answer and smile at their ineptitude.

My wife and I are vacationing later this month in Rome for two days, a week in a villa in Chianti and finally two days in Florence. We'll be doing a day trip to Sienna and Montalcino and maybe another day in Lucca with our rental car. Barring catastrophe, I'll post pictures here next month when I get back.

I'd like to tap into the UHH brain-trust and all suggestions are welcomed especially concerning where the best spots photographs & short videos are allowed and what problems to look out for.

I'm second guessing my original plan to pack my full equipment backpack (Canon 5ds, 70d, Ricoh Theta-S, 10-18mm, 18-135mm, 35mm 1.4L, 24-70mmL, 100-400mm L, 320EX Speedlite, Manfrotto Travel Tripod, batteries, chargers, filters, etc.)

I've been forewarned about thieves in Rome; is Florence risky as well? (bear in mind, I live in Chicago :-)

I can tell you right now that regardless of your experience with Canon the way you are trying to conduct business is not the right one. We like to see someone well identified and familiar to the forum. I guess you have not done your homework because it is evident that selling camera gear it is a must to show pictures to others of the items that are for sale. That helps a lot and makes others take decisions.
Begin by identifying yourself and showing where you are located. Show pictures of the camera and your accepted method of payment along with the price you are asking.
Those guidelines in general work very well for the seller.

A quick show of hands please. How many photographers here are also musicians? I find it interesting that so many people who are "artistic" often are so in more than one discipline. Ansel Adams was also a classically trained pianist, you have Ralph Gibson, and more recently people like Brian Adams, Nikki Sixx (no joke!), and Graham Nash. All are well known musicians and are also Photogs. My father was a photographer and jazz drummer who must have rubbed off on me because I'm also a musician in addition to being a photographer. My eldest son, who plays multiple instruments, also has a keen eye for photography.
I'm sure that there have been many studies on this, but I'm just wondering how many in our little community practice both arts.

I am up in the Blue Ridge mountains and the flowers are starting to bloom. Thinking about a series - dogwood, azalea,redbut and rhododendron. All I have with me are four small prime lenses - 18, 25, 50 and 85.

Do I need a macro lens? Weather is stormy and light is flat (similar weather to Augusta). Think maybe the dogwood would make a good high tone image.

And it is windy so will need to shoot rather fast. DoF will be difficult with the 85mm.

Am I trying to do the impossible?