Feinstein is in extremely bad health and is basically being used as a Weekend At Bernie's puppet at the moment. She is 89 years old.
However writing to her is not going to help change anything
Right wing nominated partisan hack judges are one of the biggest issues facing our country right now. It's one thing to have a partisan judge that always leans one way when making decisions. It is another to just totally disregard the law and make things up to fit your agenda. (see Judge Aileen Cannon or Judge Matthew Kacsmaryk).