Does the 2023 1099-R need to be corrected for the period of time she was a nonresident? - No

Can the taxable amount be adjusted for the period of time she was a nonresident and not have a 1099-R reissued? - Yes

In Screen 13 Pensions, IRAs (1099R), create two payers: both Calpers

In the first Calpers, designate State = CA, and enter Gross distribution, Taxable amount, etc. (except State tax withheld) = 41.7% (5/12) of the amount shown on Form 1099-R. Enter State tax withheld = 100% of the amount shown on Form 1099-R.

In the second Calpers, designate State = WA, and enter Gross distribution, Taxable amount, etc. (except State tax withheld) = 58.3% (7/12) of the amount shown on Form 1099-R.  Enter State tax withheld = 0.