Recently switched over to DuckDuckGo on all my devices. Tried to do the same thing several years ago and found it didn't really work out, but this time around it is so much better, both when it comes to speed and results. If anyone has doubts because they tried it years ago, I'd say go for it again.
The problem is, whenever you can't find something in DDG, you assume it's because it's DDG, and search again with !g. Meaning I end up requerying 40% or so of my searches using !g (prefixing your query with !g redirects your query from DDG to encrypted google)
Here's some example queries I ended up !g yesterday that had much better results in google than DDG:
reduce kendo javascript file size - For me, the useful result was number 2 in google. In DDG it was number 11 ("Only What You Need | Kendo UI Getting Started").
ptr overwatch - PTR is the test patch of the game overwatch. It's regularly changed. The correct result "Overwatch PTR Now Available - August 29, 2017" is number 1 in google, in DDG the blog post August 12th is not available (well, correct from my perspective)
I tend to find anything speculative DDG is fairly terrible at. For example yesterday I was googling about trying to identify the source of some weird animation CPU cycles I was seeing in Chrome Performance Profiler, I didn't really get to the bottom of it, but I ended up ditching DDG and doing all the queries in google because I would otherwise have ended up searching everything twice.
I'm also getting quite frustrated with the "instant answer" functionality, it's generally terrible. One of the most annoying ones is the SO instant answer that just utterly sucks, you can't see the code, it usually cuts anything useful in half, and takes up a HUGE amount of space meaning on a laptop you've got to scroll to start seeing the results. I just want to be able to turn it off, but because they don't track you they don't offer that functionality.
Also the maps one is really bad. I almost always want directions, but clicking the map takes me to a really nonfunctional, bare-bones map that doesn't have directions and then I have to click another button to actually get the directions. There's a drop down where you can choose your map type, but it definitely doesn't work as expected, I just want it to always embed a google maps instead of whatever they're doing.
Basically UX ain't DDG's strong point.
Ironically, if you DDG: "turn off certain instant answers duckduckgo" it comes up with terrible search results and no answer. If you "!g turn off certain instant answers duckduckgo", the top result is at least relevant.
I also find the entire bang thing to be a gimmick. Who wants to use !r when !g with "reddit" at the end will always get you better search results, reddit's own search is abysmal (as is !so).
EDIT: I'm being overly negative, after all, I haven't actually switched back, like I did last time I tried to use DDG. So it's definitely worth a go, but I don't think it's ready for your Mum to use. Also, I have Bing on my phone's Chrome to avoid AMP, and it's actually quite good.