r they playing or fighting?

Ok my bella is in a playful mood(i brought out the shoe string) but first i seen her and stormie going at it i know stormie is playing but how do i kno if bella, how can i tell between rough play and fighting. I didnt hear no growling, or any noises i just seen paws flying, bella had an evil look in her eyes idk maybe i am over reacting i dont want them to rough play but i do want them to play together but how can i tell the difference from rough play to fighting?? A few minutes ago bella was cleaning stormie which i never seen her do before and i cant figure it out maybe they are getting closer any ideas? I caught them a few times laying next to each other but that was it and now bella's cleaning her and idk if bellas had kitten before because i found her and when we took her to the vet they said she has scars so she was already fixed. But ya i just dont kno and bella is now looking around the room in this box my mom gave them and i put her play to in it and she played for a little bit and now she is looking around the room, could she just be playing with stormie or mad because she tried playing with her?? PLEASE HELP cause now bella is giving me sad eyes and looking up at me, and im going crazy cause i dont kno what to do please help me

they are playing, especially since there is no growling or hissing. bloodshed is a good way to tell the difference.

ya but see also sometimes bella randomly goes up to stormie and puts her paw up and claws her, and thats what she does to the dogs she use to hiss and growl but she hasnt recently, thats why i am wondering if this is play or not you know its just so confusin, bella isnt growling or hissing she used to at the dogs now she doesnt she just puts that paw up if they come to close thats why i am so confused and the kitten always wants to play so i am hoping that they are playing but i am not sure because of how bella is u kno, these cats make me worry too much !!!! lol

It all sounds pretty normal to me. ANY two cats living together will sometimes get into it for what seems like no reason to us, but they have cat reasons, and it doesn't mean they're not friends any more, or that they want to kill each other, but that sometimes they're maybe just bored, or have had enough of the other one for a little while, or they want to be #1 that day, or who knows! Don't go reading bad stuff into everything - as long as they act normal afterward, and haven't actually done much damage, it's just what cats do and I wouldn't worry a lot.

As long as they're not crying in pain or there's blood flying everywhere, then it's play and you prob. don't need to worry. Larke pinpointed it.