Well thanks for all the advice - it seems to have paid off. At 12.00 noon today I spotted babies with both mum and dad in attendance.
I fed them some frozen baby brine shrimp - which dad ate most of and then again at 3.00 - which dad had most of.
I put a stocking over the fluval filter as it is very strong in this 72 litre tank - I was a little frightened that the distrubance would panic mum into snacking on them. But she was just picking them up and moving them elsewhere.
I have been putting the baby brine shimp in with a large kitchen baster in the hope of getting them near the fish but hey that is easier than it sounds. I also have cyclops and liquifry 2. I will give them some liquifry this evening.
Would I have to do small frequent water changes to maintain water quality. Good fun isn't it when something like this happens.