How should a woman prepare for US Navy SEAL training?

Keep your head on straight. Never been there, never will. Things to remember: you know your body better than anyone else. As already stated, there are a lot of workouts you can access, so find what fits you. Female bodies are not the same as males. This is an extreme course designed to weed out and accept only the very top, best of the males. No matter how or what you think, a female body is not the same.
Yep, you will have a mental part to get over, this you can control. Don't let "stuff" get to you, it is designed to. All you can do is your best.

Jasmine Joy Maybe you will be the first female Navy Seal. Good luck.

Have any completed it to redieve their trident?

not a SEAL, (prior USMC/USCG), so take this for what it may or may not be worth. Of course the mental and physical preparation should be as demanding as you can possibly make it and as in all military indoctrination, don't be the "one that sticks out", you are female, no way around that, but blend.......cut off your hair, same length as everyone else, ...........not sure what you think you are getting into, but realize that the psychological angle will be very important, you must acquire the correct mindset and unless you have been around males most of your life, you will be at a disadvantage, think (Lord of the Flies type environment)..........................
Good Luck, remember, some female will eventually be the first, why not you?

Another cautious point to consider is MST... It happens... It's a man's world. Good luck in your future choices.

PLEASE actively search for a YouTube AudioVideo song titled "Wrong Side of Heaven"
by Five Finger Death Punch to try understanding veterans like me especially combat injured and combat participants to try to understand Complex Post Traumatic Stress Disorder and Post Traumatic Stress Disorder - special forces have non disclosure agreements or n.d.a.'s due to conducting activities that is why there are veterans who become disillusioned with what they did that is a reason for why become addicted to overusing or megadosing on legal substances especially illegal that leads to unpredictable violent deeds including becoming homeless - contact a S.E.A.L.\B.U.D.S. training center that you might have done before posting your question. your question will not be easy to reply - history reveals that natural born female warriors are awesome as natural born male warriors due to being determined to do what it is believed what it is to be done including dying even though overall the males are physically stronger - 1:05 pm Pacific DayLight Savings Time on Wednesday, 20 March 2024 on a leap year - over and out - end of line

As in any Special Force (Navy Seal) type training, you must get your physical and mental endurance as strong as possible. Get used to very cold water, be an outstanding long distance swimmer, be able to hold your breath a long time, a long distance runner (wearing boots and uniform), long ruck marches (12 to 18 miles straight with 35-65 lb ruck sack, boots, uniform, web gear, filled canteens, weapon, ammo, radio, etc.), and be able to do many many setups, pushups, chin-ups, and every torturous calisthenic that you think of. You will be sleep deprived throughout all of your training, but still expected to perform and test daily. Team work is most important. If someone gets punished, all must drop down and take the same punishment. Once pure teamwork is established, they will be a little easier on you. Good luck. Navy Seal is probably the toughest physical test of all of the Special Force type trainings.