This explanation is not mine and I took it from Narcis320 in the dev log if you want to read their full explanation you just need to go there:
You must have your level below 100 and your appearance/endurance/intellect/agility/charisma must be below 50 if you are above try using cheats (preferences->cheat code) and use Burned Cookies to decrease your stats.
And you must pass her requirements (not all):
- appearance >=12 +1 (differend text if you have appearance >= 20 or below 12)
- charisma >=20 +1
- endurance >=20 +1
- endurance <10 -1
- agility >=20 +1
- intellect <10 -1
- ExpAss() >=3 +1 (Anal, Sexual Experience)
- ExpCock() >=3 +1 (Cock, Sexual Experience)
- ExpMouth() >=3 +1 (Mouth, Sexual Experience)
- ExpErotism() >=2 +1 (Erotism, Battle Experience)
You need to get 5 points from her examination to pass.