In the present-day American midwest, a heterosexual couple (in their early twenties and in good physical health) is held captive by kidnappers. They have unprotected consensual sex, by which she loses her virginity. The morning after, the female member of the couple goes through her typical morning routine (evacuates bladder, though does not shower). She then gets into a fight with said kidnappers and is clubbed in the head with the butt of a handgun, and falls to the ground, losing consciousness. She's taken to the hospital and is given a rape kit about 12-15 hours after having had sex.
1-If she could experience retrograde amnesia (from a concussion as a result of being hit by the gun and/or falling), could said amnesia extend to her memories of the night before, i.e. that she had sex? Also, is there any guideline about how long it would take her to recover the memories? Would a week be out of the question? A month?
2-Would the rape kit find any DNA evidence that had not degraded past the point of definitive identification? I can't find anything specific about this, just the usual "isolate and keep the samples contained, possibly frozen, as quickly as possible."