What was the sin that led to the offering in Leviticus 15:30?

Answer From The Annual Reading Schedule - Week 27 Notes For Leviticus: Again, the discharge is listed in verse 30 as the reason for the sin offering for atonement. Could the extra bleeding or discharge she is going through be a result of some sin? Possibly, but that doesn't mean we can say that is the case in all situations. All we know for certain is that a sin offering and atonement are needed when there is abnormal bleeding or discharge. Again, this could possibly be related to the fact that this flesh is corruptible and how imperfect it is. Read the reading notes for Week 25 of the Annual Reading Schedule, specifically the answer for the question "What was the sin offering for in Leviticus 12:6?" for more comments elaborating on a similar situation which may help understand this idea more.