There's only one drawback to a Chromebook, if you can live with it: It's just one big browser. All apps run in a web browser, Google Chrome to be specific. There is no Windows operating system, so you will not be able to install or run any Windows programs. If that's not a problem then a Chromebook is a great idea.
Well, it is true that software runs in the browser. However, browsers aren't what they used to be. Unless you're a gamer, how much time do you spend on the internet/word-processing? Think about it.
Remember, there are also offline apps too.
The Chromebook has replacement apps for many windows functions which work very well, like text-editing, presentation making, filling in spreadsheets, communicating using VOIP with several others in HD, etc.
Yes, there are programs which Chrome OS won't run. But how many of those programs will be of use for Taylore12's mother? Next to that, how many will run on a 300$ PC ? (chances are you'll be stuck with a AMD E1 with 1.0 GHz {remember 'good speed' was specified}, I'd like to see 4K video editing on that)
Honestly, for someone who is just looking for getting the basics (and a little extra), an easy to use UI, awesome features and speed, get a Chromebook.
I fix and sell computers; I own all types of computers running the main 5 OS's. When I sell a computer to someone, I make sure that they get what they need, and don't pay more for anything they don't want/need, and have never heard anyone complain. Chromebooks are brilliant laptops.