不是省不省略的问题.Her work done, Her work being done, her work having been done都是可能的,但是意思各不相同.Her work done, her work having been done都表示她的工作已经完成,可以互相代替,her work being done则表示工作正在被完成.你得根据句意选用正确的形式.本句能用Her work done, 或 her work having been done,她在完成工作后再去喝茶的.请注意,用her work having been done的话,be 动词变成了been并没省略.