Excellent! It's a very big thing to have the peace of mind knowing she isn't loaded up with zinc. And if it is Marek's, since she's been vaccinated, she has a better chance of living with it since the vaccine prevent tumors. B-complex can help, and also you might try Valtrex (acyclovir) to alleviate the worst of her symptoms if it is Marek's.
Valtrex is a human prescription med that treats herpes virus lesions. I take it for shingles outbreaks. Since Marek's is caused by a strain of the herpes virus, Valtrex may help. We don't know. It hasn't really been discussed much here on BYC the connection between avian herpes and human herpes and reported experimenting with an anti-viral herpes med.
The problem is getting a prescription. If you ever suffer from cold sores, you could ask your doctor to prescribe it for you. Yes, I know this amounts to subterfuge. I like to call it "ingenuity". When I experimented on some pullets some years back, when I suspected Marek's, I broke one pill into quarters and gave a quarter pill per day. This is all the literature I could find on this.
https://poultrydvm.com/drugs/acyclovir
I can't really say if it had any effect on my pullets. They were later diagnosed with lymphoid leucosis which is caused by an entirely different virus.