The specialists can do no more for my dog who was diagnosed with pneumonia (misdiagnosed with cardiac failure by my vet!) and has spent a week in intensive care.
She has made progress and is eating now well. Her problem is her breathing and oxygen saturation levels in her blood, which are low despite receiving O2 via a nasal catheter.
She is hopefully coming home on Friday once having a trial tomorrow without oxygen and see how she copes. She is to have strict cage rest, antibiotics for 4- 6 weeks and wait and see.

What are the best supplements I can give her to help improve her chances of recovering?
She may in the future need a lung lobectomy if the infection is persistent and damage irreversible.

Ahh  you've been through a rotten time :-(

Zinc is good for the immune system and can aid recovery  http://www.bbc.co.uk/news/health-21372790

Also garlic,  my father used to use it for his chest,  mashed up well and mixed with oil,  and spread on his feet at night (then plastic bags covered by socks!)  q   in the morning his breath would stink of garlic.   His chest would clear a lot faster,  but it did make him cough (very 'productive' too)   Not sure how you could apply this to a dog,  but it works better by- passing the stomach.

It might be worth a phonecall to Dorwest Herbs Dorwest Herbs,  to see if they can recommend anything.

Hope you can get her well again without more veterinary intervention.

Mmmm garlic on four paws & socks might be a tad tricky on a dog😝.

Just hoping that being at home will maker more relaxed. Yesterday was a such a good day but overnight her O2 sats dropped. She hadn't eaten for 8 days, she must feel a bit better to now want food.

If you look online for garlic and pneumonia,  there's the suggestion of breathing it in too ;-)

Dorwest do Garlic juice and it may well be possible to massage it onto eg the tummy where it would be absorbed through the skin.

I'm sure being at home will be a huge benefit,  the stress of being away from her humans and home can't be helping.

It might be worth a phonecall to Dorwest Herbs Dorwest Herbs,  to see if they can recommend anything.

Totally agree with this - or you might call Ainsworths.   If you can find a vet who specialises in 'alternative meds', that might be a good idea too although I'd suggest your treating vet should be able to advise?   I think you do need to find something that concentrates on boosting the immune system.   But I'm no specialist in this area!!