Fast[er] and big[ger] is great, but she could easily do this with* a toaster, baby AT mobo, and a 486/66 Mhz with 64 MB RAM at no more of a load than what's she's describing. It'd do mail, too, and you could chase Klingons around from the CLI in your spare time 😃 'Course, it'd be a PITA to do any big compile ops --- e.g. FreeBSD's "make world", for example.
But this is exactly the situation where Open Source stuff excels. Get a retiring Winbox, blow out the dust and stick Gentoo, Slack, (or, yeah, FreeBSD!!!!!!) on it. "cd /usr/ports/lang/php4 && make install clean ..."
voila...
My first server was a Celeron 233/64MB that had begun life running Win95. I seriously think it ran until just last year, and I only replaced it because I had faster junk I'd never use for anything else ...
[*realistic example, perhaps, but just an example, nonetheless ... finding AT keyboards is getting harder, heh!]