Linux mint is a good, “click first” distro that won’t break without root + will be easy for her to use. For something with a more modern desktop and more recent updates, Bazzite is really good at just working and (in my experience) has never broken

Debian can be pretty light/small on a clean install and xfce should run fine on 2gb. Although the biggest thing is gonna be if the laptop has fast storage or not. Since its a celeron it might not be upgradeable, and if it doesnt already have an SSD any desktop will feel slow

Personally if I really wanted to squeeze all the performance I could for web browsing I’d go with minimal Debian and RiverWM but thats a bit more involved

In a similar vein I really miss rainmeter, now I’ve gone down the deep rabbit hole of EWW and AGS but rainmeter was way easier