Post to the prison takes about 4 weeks and may never anyway reach Marianne. 

The best way is to send a fax via her mother, Sheila, on
0018 09 5865202

Mark it for the attention of Sheila Telfer and send it around 5pm-6pm. when the hotel fax is usually switched on!

You can also contact Shelia by e-mailling
contact@Justice4Marianne.com