I know you mentioned large screen and proper keyboard but has she had chance to try a larger tablet not necessarily ipad.
For mainly web use and email they are pretty bomb proof and she might get on better than you think with the alternative keyboards you can add on like an app.
The old computer ought to still be able to connect either with ethernet cable or a USB (plug in) wifi dongle.Windows 7 is not that ancient.
However a newer one with SSD and Windows 10 will be considerably faster even with modest specs.
The one thing I don't like about W10 is no longer being able to stop their constant updates and more than once they have slightly broke my two e.g. knocked out audio until driver was rolled back.