Lieutenant Mary Sue is a half Vulcan and the youngest graduate from Star Fleet Academy. She was immediately assigned to the Enterprise due to her incredible ability.

She was known for her beautiful youth and youthful beauty, intelligence, capability and all around niceness.

The full text of A Trekkie's Tale by Paula Smith can be found here.

Strength

• She does not have any direct strength feats but she is a half Vulcan.

In a moment of weakness Lt. Mary Sue revealed to Mr. Spock that she too was half Vulcan.

Vulcans and half Vulcans are 2-3 time stronger than humans.

A different half Vulcan, Mr. Spock, has been shown to be able to,

• Bend thick metal rods and punch humans a few meters

• Smash a computer monitor

Speed

Probably about what you would expect out of a fairly athletic person.

Durability/Endurance

• Resisted Captain Kirk's advances,

"Gee, golly, gosh, gloriosky," thought Mary Sue as she stepped on the bridge of the Enterprise. "Here I am, the youngest lieutenant in the fleet - only fifteen and a half years old." Captain Kirk came up to her.

"Oh, Lieutenant, I love you madly. Will you come to bed with me?"

"Captain! I am not that kind of girl!"

• Was able to run the Enterprise better than anyone even while sick with the cold robbies.

But back on board, Dr. McCoy and Lt. Mary Sue found out that the men who had beamed down were seriously stricken by the jumping cold robbies, Mary Sue less so. While the four officers languished in Sick Bay, Lt. Mary Sue ran the ship, and ran it so well she received the Nobel Peace Prize, the Vulcan Order of Gallantry and the Tralfamadorian Order of Good Guyhood.

• [Limit] She died due to contracting the cold robbies

However the disease finally got to her and she fell fatally ill. In the Sick Bay as she breathed her last, she was surrounded by Captain Kirk, Mr. Spock, Dr. McCoy, and Mr. Scott, all weeping unashamedly at the loss of her beautiful youth and youthful beauty, intelligence, capability and all around niceness. Even to this day her birthday is a national holiday of the Enterprise.

Intelligence/Skill

• Ran the Enterprise so well (while being deathly sick) she receives a bunch of prizes including the Nobel Peace Prize.

But back on board, Dr. McCoy and Lt. Mary Sue found out that the men who had beamed down were seriously stricken by the jumping cold robbies, Mary Sue less so. While the four officers languished in Sick Bay, Lt. Mary Sue ran the ship, and ran it so well she received the Nobel Peace Prize, the Vulcan Order of Gallantry and the Tralfamadorian Order of Good Guyhood.

• Mr Spock admires her mind and thinks she is "flawlessly logical" even though she did not make the decision he is complimenting.

Mr. Spock came onto the bridge. "What are you doing in the command seat, Lieutenant?"

"The Captain told me to."

"Flawlessly logical. I admire your mind."

• Picks a lock with a hairpin

Recovering quickly, she sprung the lock with her hairpin and they all got away back to the ship.

Other

• The loss of her beautiful youth and youthful beauty, intelligence, capability and all around niceness caused grown men (including a Vulcan who would be suppressing his emotions) to cry unashamedly.

• She was so amazing in life that her birthday is a national holiday of the Enerprise

However the disease finally got to her and she fell fatally ill. In the Sick Bay as she breathed her last, she was surrounded by Captain Kirk, Mr. Spock, Dr. McCoy, and Mr. Scott, all weeping unashamedly at the loss of her beautiful youth and youthful beauty, intelligence, capability and all around niceness. Even to this day her birthday is a national holiday of the Enterprise.