I think her intent would be to hang on until the 2024 election cycle, where she would retire and not be replaced until after the "people have spoken" in Nov 2024. So 5 1/2 years would get her there. I'm not saying any prayers for her...
It would be poetic justice if she hung in there that long only to have Mike Pence win the presidency in 2024.
There was the Scalia (Garland - not acted upon) Gorsuch seat in 2016. Republicans controlled the Senate.
I think Kennedy 1988 does not count - the vacancy was 1987.
Democrats controlled the Senate - could have played hardball, although we know now why Cranston supported Kennedy.
Warren 1968 - (Fortas - scuttled), then Burger appointed by Nixon. Democrats controlled the Senate.
Brennan 1956 - recess appointment. Democrats did control the Senate but they were adjourned at the time. Eisenhower’s motive was to appeal to urban Catholics, and of course that backfired. They probably weren’t expecting Minton’s resigbation.