My veiled chameleon is a bit older than yours and I started having problems with MBD just about the same time as yours. Just correct her supplement schedule. Calcium WITHOUT vitamin D3 at every feeding, Calcium WITH vitamin D3 twice a month and a multivitamin twice a month. As long as she's still eating, that should help stop the MBD from getting worse.
How does her poop/urate look? What are you feeding her?