It has been recently suggested on ROC Chat that O’Connor would have been a good replacement for Tasha Yar. Nonsense. Crosby’s departure was a really good thing for Trek that resulted in Worf becoming Security Officer and the best episode of the series (Yesterday’s Enterprise). When STTNG began, O’Connor was rather young (about 16) and might well have been written into the show as Wesley Crusher’s sister.
Now, were one to consider DS9, she might have pulled off an incarnation of Dax.