I have heard/read there is a lot of confusion regarding who was martyred in the dungeon after the martyrdom of Imam Hussain (as).
Was it the young girl of 4-5 years of age janabe Sukayna or janabe Ruqayyah? Also there are narrations that Imam Hussain (as) had 3 daughters. While some have said He (as) had 2 daughters. That is janabe Sukayna and Ruqayya is the same daughter of Imam Hussain (as).
Would be grateful to clear the confusion.

Sakina was the teenage daughter of Imam Hussain (as). Ruqayya is the 3-4 year old daughter of his. She is the one who died in the dungeon of Yazid. Sakina is also buried in Syria as well. The urdu speaking community refer to both of these daughters with the same name which is why there is confusion. There was another daughter who was left in Madina because she was ill.