Legendary Divas like Mariah don't need redemption. That is something for lessors. What the Queen needs to do (apart from getting proper rest and vocal exercises) is record various prerecorded vocals for any overly difficult notes or for if she has a bad day. Most importantly, she needs to work on her presence! If she's going to lip sync, it has to be done with finesse like Celine Dion. Celine has lipped half her shows since 1998 and people are still surprised to find out!