There are four main options:
Cable Internet access
Is she in an area where she can get cable Internet access (most probably NTL/Telewest)? If so, this would be preferable to ADSL. On the other hand, unless the house is already cabled, it will require physical installation (possibly even digging up the road/pavement outside) which, I assume, would be out of the question given her situation.
GPRS Internet connection
If she can get a GPRS mobile signal (which is most probably the case, unless she lives right in the centre of the middle of nowhere), she could surf the Internet using that. She could link her phone to her laptop (using a USB cable, or possibly via Bluetooth) or get a PCMCIA card which allows her to insert a SIM card and get surfing that way (these PCMCIA cards have been advertised by Vodafone quite a bit, but I assume other network providers offer similar solutions). Unfortunately the speed wouldn't be too great (probably about the same as you'd expect from a dial-up connection) and as it stands GPRS data transfer costs quite a fair amount of money. For occasional but necessary access (downloading emails, checking one or two websites etc.) it should work out fine, however.
Wireless Internet connection sharing
If her neighbours have the ability to get an Internet connection, or have one already, this would probably be the easiest option. She could offer to pay part, or all, of their Internet connection costs, buy them a wireless router and set it up so she can access the Internet via their connection.
Satellite Internet connection
If she really does live right in the centre of the middle of nowhere, and speed is an absolute necessity, she could get up-to broadband speeds (~2Mbps) from any number of satellite ISPs. The latency will be shocking, but it would be more suited than GPRS for downloads. It would cost an absolute bomb, however, and if she is unable to install a phone line I doubt she'd get away with installing a hunking great satellite dish on the roof! This would only be a "my life depends on getting a broadband Internet connection, and money is no object" solution, unfortunately.