Mum tripped whilst walking along Terrigal Esplanade

Seeking some advice on whether I should look to make a claim against Central Coast Council for a raised manhole cover on Terrigal Esplanade.

Mum (68) tripped on a raised manhole cover that was 15-16mm above the normal surface level of the footpath in a high traffic area (right outside several restaurants). The fall caused a non-displaced fracture in her non-dominant hand and a severe concussion. She required an ambulance and hospitalisation as a result of the fall.

We've got photos, witnesses, measurements and obviously medical reports. I've reported the issue to the Council as a risk to the public.

Further to this when I went to get photos yesterday I sat and watched people walking over the same manhole cover for 30 minutes and in that time I saw nine people catch their foot on the cover with three of those people actually stumbling (one was a mother carrying a baby).

I'm not a huge fan of litigation for this kind of thing, but I feel that in this instance, I want to take things further. Mum and dad were visiting me from the UK and it was likely to be their last trip here for financial and health reasons. The fall happened 2 days before they flew home and its just left us all quite shocked and ruined the end of their trip.

If I take this further, what are my chances of getting any financial compensation? Should I even bother?