My thought too, but apparently it's a no.
Can she get him along to a store to see how the iPad looks and works with a keyboard cover? It sounds like an ideal fit for the use case, and sometimes it just needs someone to see it looks like a laptop to get them off the idea of 'I don't want a tablet' - they're not stupidly cheap to purchase, but they really are a lovely size and should last for years without getting clogged up.
Would suggest somewhere like John Lewis, where it doesn't feel too 'tech-y' - we just picked one up from there as they had an offer on the keyboard cover, got the 64GB iPad Air and cover for £550.
If it really is a no, how about the MacBook Air? I'm still using my mid-2012 model for design work so even that would be over the top for email and browsing!