Welcome to icliniq.com.
I read your query and understand your concern.
According to your description, it is very rare to get pregnant in such situations, because sperm cannot live more than one to five minutes outside the human body. So the semen on the thighs will not cause pregnancy. And if her due date is in the next three to four days then that was her safe date, that means even if you had unprotected intercourse it would not have caused the pregnancy.
So she does not need any contraceptive pills like I-pill. Unnecessary hormonal pills will disturb her menstrual cycle.
I hope this information helps you.