Don't be afraid of adaptation. If your mom is normally lucid that age isn't a problem to learn a little bit.

My mom started with a Motorola MicroTAC Elite in the late 90s and then went to my Nokia 1100 after i left it. Now she is 60 as well and i gave to her (forced by me :P) my old Nokia 5310 before buying my 5230 (if you look at my timeline down in this post you'll see later i sold the 5230 and finally bought the N9).

She has learned to use the 5310 very well at least with calls and SMS uses, although she didn't wanted to learn how to take a picture, listen to the radio or browse the WAP Web. But that's because she didn't WANT to, i'm perfectly sure she can, but don't wanting to is another story. She uses the options menu and the dictionary while writing SMSs, manages tha contact list and many other advanced things.

Arm yourself with some patience and buy her the most common and cheap phone you can find from Nokia, Win7Mac has given you two excellent choices. Then after a week and some "how to do" reminders she will be on her way, specially if her comes from an early Nokia phone.

My mom even uses my N9 to make calls whenever she wants, because i've a much bigger contract than hers and it serves well for long distance calls. I've teached her how to unlock it and browse to the apps view and pick the green phone icon, the hardest part was telling her no to hit so hard the screen while using a touch phone (nearly all the people 50+ years old think the new phones screens are like the hard-to-press old ATMs touchscreens, haha). I even think you should try a touchscreen, I have strong suspicions that the new smartphones are even easier to use to older people thank mos of us think.

Good luck!