Get your Mum a Volkl V1 Classic. Volkl makes an excellent product and they are very comfortable.
I just demo-ed the new dunlops f 3.0 and m 3.0, wilson ps 6.1 95, and tecnifibre v02 320 against my current racket Volkl O10 295 customized. My racket is far better than all of them.
Volkl is an EXTREMELY COMFORTABLE racket.
Volkl is an excellent choice and the V1 Classic is perfect for a good player that is getting older or an intermediate to advanced player looking for a light racket with power and control.