By Seamus Duff The Masked Singer had a bonus judge for the 2023 Christmas special – and fans were loving her. Leona Lewis was a surprise guest on the madcap ITV show \- and opened the show with a rendition of her festive song One More Sleep. The contestants of the 2023 special, which were dressed as a sprout, a partridge, a reindeer and some Christmas decorations, were singing around Leona – while she performed from atop a tree. The 38-year-old singer then took a seat alongside the panel of regular judges; Davina McCall, 56, Jonathan Ross, 63, Rita Ora, 33, and 35-year-old Mo Gilligan Joel Dom…