What is a shorty carto? I am only a month into vaping but I am an electrical engineer so the coil making wasn't even an issue. I use an Aspire Nautilus and have ordered a Patriot rda. Outside of those two types I know nothing about the other types of atty tech.
Not sure what your Mom has tried so far. You mentioned leaking issues so I have to assume some type of clearo.
Cartos predate your devices mentioned. Normally they are standalone devices, that have polyfill and a coil in the same unit. You saturate the polyfill, it feeds liquid to the coil. But they aren't without their problems: If you let the polyfill run dry you can singe the polyfill - rendering it nasty and useless. They have a central vent tube - similar to a clearo - and if you get liquid in there it can leak right out the bottom. However, using a carto on a Reo largely eliminates both those problems. It's easy to keep the polyfill wet squonking a Reo. And since a Reo is designed to bottom feed, any leaking out the bottom of a carto is simply a non issue - it drains right back into the Reo.
They are disposable and cheap. Normal use is typically an average of six days. But I've had cartos running over two weeks on a Reo and still working. Standard length cartos would work too, but the shorty just has less polyfill - less to bother needing to saturate with a squonk. Like these. You can see the shorty on the left compared to a standard length carto. =>
Mini Resurrector Stainless Steel 510 (5-Pack)
The Ikenvape attys? Small silica wick with a coil. Same deal as a Reomizer: Needs more frequent squonking to keep the wick and coil saturated. They can be cleaned & dry burned but they are still disposable. =>
IKV io6 LR Atomizer 1.8 My only complaint about the IO6 attys is they have been inconsistent of late. Some times they last weeks before a coil pops, some times only a few days. (They do have a two week warranty though.)
The Joyetech 306 atty is similar.
Either the cartos or the atty require a drip tip.
One versus the other? Up to Mom to decide. Different people say they get better flavor out of an atty versus a carto - and the other way around as well.
Best topper for a Reo is one thing. Best topper for your Mom for a Reo - that could be something else. These are her non rebuildable, screw on & go options.