The fight had started when Morgan had stolen a locket Harley parents had given her before the had died
Morgan was planning to sell it, and keep the money 
Harley tracked down Morgan to get her revenge but Morgan was too strong and wounded Harley and had almost tried to drown her but didn't even mack it to the water because Harley had grabbed the sharp piece of the locket(it was triangular shaped) and stabbed Morgan in the leg 
it didn't make a deep wound but stalled Morgan long enough for Harley to fly away despite her wounds. 
Too many words 