Here is the "official" rules:
b. Women. Hairstyles shall not be outrageously
multicolored or faddish, to include shaved portions of the
scalp (other than the neckline), or have designs cut or
braided into the hair. Hair coloring must look natural and
complement the individual. Haircuts and styles shall
present a balanced appearance. Lopsided and extremely
asymmetrical styles are not authorized. Ponytails,
pigtails, widely spaced individual hanging locks, and
braids which protrude from the head, are not authorized.
Multiple braids are authorized. Braided hairstyles shall
be conservative and conform to the guidelines listed
herein. When a hairstyle of multiple braids is worn,
braids shall be of uniform dimension, small in diameter
(approx. 1/4 inch), and tightly interwoven to present a
neat, professional, well groomed appearance. Foreign
material (i.e., beads, decorative items) shall not be
braided into the hair. Short hair may be braided in
symmetrical fore and aft rows (corn rowing) which minimize
scalp exposure. Corn row ends shall not protrude from the
head, and shall be secured only with inconspicuous rubber
bands that match the color of the hair. Appropriateness of
a hairstyle shall also be judged by its appearance when
headgear is worn. All headgear shall fit snugly and
comfortably around the largest part of the head without
distortion or excessive gaps. Hair shall not show from
under the front of the brim of the combination hat,
garrison, or command ball caps. Hairstyles which do not
allow headgear to be worn in this manner, or which
interfere with the proper wear of protective masks or
equipment are prohibited. When in uniform, the hair may
touch, but not fall below a horizontal line level with the
lower edge of the back of the collar. With jumper uniforms,
hair may extend a maximum of 1-1/2 inches below the
top of the jumper collar. Long hair, including braids,
which fall below the lower edge of the collar shall be
neatly and inconspicuously fastened, pinned, or secured to
the head. No portion of the bulk of the hair as measured
from the scalp will exceed approximately 2 inches. <Figure
2-2-2> refers. A maximum of two small barrettes/combs/
clips, similar to hair color, may be used in the hair.
Additional bobby pins or rubber bands matching hair color
may be used to hold hair in place, if necessary. Fabric
elastics bands are not authorized. Hair ornaments
shall not present a safety or FOD (Foreign Object Damage)
hazard. Hair nets shall not be worn unless authorized
for a specific type of duty.
HOWEVER! Some females have been allowed to have their hair braided or in short weaves..BUT, it is NOT uncommon to have some RDC's(instructors) mandate your hair taken out of the weave and cut to regs. Just understand that the navy is the ONLY branch of the service that still requires females to have their hair cut! This has NOT changed and is not expected to change any time soon or in the near future. My suggestion to you if you have a major problem with them cutting your hair..1 have it cut prior to going to boot to fit the regulations, 2 try and see if you can have a weave done to fit the regulations, 3 deal with what ever comes at boot, 4 dont enlist.
Understand it is just hair..it will grow back!