must have been/have done : question tags?

[birgit33]

"She must have been there early, didn't she?" "You have done a lot of work, didn't you?" Are the question tags "didn't she?" and "didn't you?" correct?

 

[SoothingDave]

Match the verb used earlier. You have done a lot of work, haven't you?

 

[Raymott]

"She must have been there early, mustn't she?"
However, it's not common to use a question tag with "must". If you are confident enough to say that something "must have been", you don't usually express doubt with a question tag.​