Dorrie, by english folk music, I presume you mean "from England" rather than "in English".

Start her off with some samplers. There are plenty of "Best of English Folk", "Cream of British Folk" etc CDs going cheap (£10.99 for a double or even 4-CD set). These are not too hard to find - available even in places like Virgin, HMV, Woolworth, Asda, Tesco.

They cover a fair range on a single record - old field recordings (Harry Cox, Pop Maynard); 70s electric (Steeleye, Pentangle); unaccompanied-ish (Shirley Collins, June Tabor, The Watersons); instrumental-ish (Swarbrick/Carthy, Renbourne/Jansch); singer songwriter (McTell); easy listening (Dubliners, Spinners). And many, many more - I found Nic Jones that way.

A couple of these will give your friend a wide cross-section of what's been recorded over the last 40 years, and should enable her to decide which direction she wants to go next ("I don't much like X, but Y is amazing")

WassaiL! V