Well, she's a Warren protege and she even named her daughter, Elizabeth, after her.
The timing makes sense given that Harris isn't remotely viable anymore. She briefly worked for Harris and generally speaking Reps don't endorse a candidate when another member of their state delegation is also seeking the office (it's terrible inside politics). Granted Feinstein did the same, but she also dislikes Harris going back to her DA days so that was probably also some shade on her end.
Anyway, it's a good but expected endorsement.
