If she's using the traditional commercial definition of hit, then, as BroadwayTonyJ pointed out, The Tap Dance Kid, Black and Blue and the Sweet Charity revival do not count as hits. Nor, for that matter, does Sunset Boulevard, even though it did win the Tony so, yeah, that is a big error.
If she's not using the traditional definition of hit, as it seems she isn't, then Irene should certainly be in there.
In addition, she points out that Pippin and The Tap Dance Kid were transfers, while neglecting to mention that Pirates and Lion King were transfers.
The first volume in the series was astoundingly error-ridden, even if you don't count the errors made by the interviewees. I haven't read any of the others.