If people are happy to let her do it all on her own then fair enough, but if someone else wants a go (which they clearly do) then they shouldn't be denied that experience, regardless of how good Charlene is.True - plus they're all saying how delicious it is so she's not doing a bad job by the sounds of it!
They need to start sharing the task before she gets too territorial, especially if her doing the cooking means she doesn't have to do other stuff like the dunny or fire etc.