Phones in England

Carphone Warehouse has basic Nokia phones for well under £10 ($15) when you buy a £10 pay as you go top-up at the same time. Vodafone is currently offering a pay as you go phone which appears to be targeted at people like your mother, for £15: http://shop.vodafone.co.uk/shop/mobile-phone/vodafone-155 You mention using the phone in Europe - using a phone like that outside of the UK is fine, as roaming call rates are capped. In other words the charges are fixed, with call rates from 1 July being limited to €0.24 per minute for a UK phone to make a call when used in another EU country and €0.07 a minute to receive a call. This only applies in countries that are members of the EU, but most networks will probably include Switzerland in the rate cap.

kathy, As Kevin mentioned, CarPhone Warehouse is a good place to buy phones as they have products from many different networks (ie: O2, Orange, Vodaphone, 3, Virgin, etc.). The staff there will be able to explain the features of the various calling plans. You could also go to one of the stores for individual networks, which aren't hard to find in just about any city in the U.K. You could also consider a phone from one of the "travel phone" firms such as Roam Simple, Cellular Abroad, Call In Europe, Telestial, Mobal or EuroBuzz (there are others). I'm not familiar with "Planetfone" so can't offer any suggestions. Whether you use a travel phone or one purchased in the U.K., you'll most likely be using a U.K. phone number. If your Mother is mainly going to be calling you, it should be easy to program your number into the phone so that she can easily call you. If you're calling other numbers in Europe with the phone (ie: confirming hotel reservations), the dialing sequence will be different in each case. Happy travels!

Are you going to be with your mother or will you be back in the U.S.? If it's the latter, you probably need a phone here that you can program before she leaves. Here's an alternative option: Get a U.S. T-Mobile prepaid SIM and put it in a simple cell with the right radio frequencies for Europe. You can buy such a phone from amazon, tigerdirect, or eBay. The phones sold with T-Mobile's prepaid SIMs probably just have the frequencies to work in the U.S. Prepaid T-Mobile SIMs will work in Europe now, but the cost per minute is high. Still, it might be what you need for short infrequent contacts.

Kathy... does she have a cell phone here in the US? Where do you plan to call?
Can she text? There are some ways to save depending on where you want to call, or does she need to be reached by phone?

My family will be traveling with her. We have a couple of phones that will work in England. She is having back spasms and is worried she will need to be separated from us at times.
Kathy

Because you want the phone for temporary absences, follow Kevin's advice and get an inexpensive phone or just a SIM when you get to the U.K. That is the lowest cost option. Just preprogram the number of your U.K. SIM into her phone's contacts so she can call you easily.