Uhh, the initial fighting was consensual combat. Both were willing participants and both stated it as such.
The fight ended when the girl in black says she is done and has had enough. When the girl in black says that and tells the girl in pink to leave it's over. The girl in pink not leaving is criminally trespassing by continuing to remain on the property and following the girl in black around in an attempt to instigate the fight further again.
If you want an analogous scenario this is like a girl saying "No" to sex just after taking off all her clothes and saying "yes" up until that point. Once someone says "No" it is over and trying to continue sexual contact is rape after that.
Continuing actions against someone that has disengaged from a given scenario is a criminal action in most cases. The girl in pink should have just said, "Fuck it, I won and I'm leaving" and left it at that. When she followed the girl in black up to her house she was leaving herself open to the girl in black being able to use up to deadly force with a weapon to defend herself now.
I consider fighting like this stupid on both parts, but the girl in pink was the stupidest in the end.