Forget the Manuka honey and get down to the GP for referral
in the meantime, try anti histamines over the counter (clarityn/benadryl)
I’ve often found that a course of antibiotics can help calm it down (eg. when its weeping, because you’ve scratched and scratched and got it infected),
old fashioned baths in psoriderm or polytar (coal tar smelling stuff) help calm it down a lot.
if she’s suffering that much then there must be some higher stage treatment to try – what treatment has she got at the moment?
I’ve suffered up and down for 24 years now, Since it flared again really bad two years ago (covering about 30% of my body) I’ve been through everything from Dovobet & Dovonex, to phototherapy, Methotrexate (which I had to stop due to liver reactions) and now I’m on a trial biological treatment, which has been a revelation, down to a couple of herald patches in the course of a month, really taken the ‘fire’ out of it)