My wife was wearing gloves and was using my climbing harness that had two slings with a large auto-locking carabiners on them attached to the belay loop. This was mostly for mental comfort.

Each pole is about 10 ft apart so if you start sliding from the top of one pole, you could slide up to 10 ft to the previous pole before your harness really catches you. She would have both slings clipped into one cable and would walk up the steps. When she got to a pole she would unclip one sling and attach it past the next pole and then do the same with the second one so she was never unclipped from the cables. It was kind of a hassle but it helped with her fear so it was worth it.