No problem about moving your thread. It helps keep us mods on our toes...
I would start free feeding her now. She is at about peak milk production right now and will really need the extra energy. Also always have hay available for her and the babies, they will start nibbling on it soon.
I know that the food available in the UK is different than in North America. But, feeding a plain pellet with out bits of fun stuff in it is best. You probably want about 16-18% protein for nursing moms and growing babies. Once the babies are about 6 months and once mom is no longer feeding babies, they should be fed a pellet with about 12-14% protein. All pellets should have a high fiber of at least 18-20%.
Hay should be given at all times. Alfalfa (lucerne) can be fed to young babies as well as any grass hay (timothy, orchard, oat, brome, etc). Once the babies are about 6 months and for mom once she is not nursing, alfalfa should be limited to a small treat amount and the buns fed mainly grass hays.
If mom is already eating veggies, then continue to feed them and the babies will start nibbling on those too. They will get their digestive enzymes from mom through her milk and will be able to eat the same diet she is getting. If she is not getting veggies at the moment, then hold off feeding them until the babies are about 4-6 months old and do a slow introduction (one veggie at a time in increasing amounts).
Since dad has been neutered for 5 weeks, I would give him one more week just to be safe and then you can start re-introducing him to mom. Do some play dates in neutral territory to make sure they don't fight. If you do introduce him to the babies, make sure you are watching very carefully in case anyone gets aggressive. Hopefully once the babies are weaned (8-10 weeks) then mom and dad will bond back together nicely. I would definitely look into getting mom spayed once her milk dries up, it will really help the bonding and it will prevent cancer.
-Dawn