How to handle an intense hater in my social/sport circle?

i think most of this petty bullshit and i hate reciting like it even matters, but she's become an issue. I need to take her out of the team, which she's doesn't really want to leave, because she's the one source of negativity and drama. Recently, she's turned on me completely and has converted Scuba Steve, one of the other players. 

our first run in; is when she fled home after one of our soccer games because apparently i said something rude and ti really upset her. i only know because she told Scuba Steve on the team who then told me.  I fb message her, already knowing she's upset with me, and mention that she took off pretty quickly after that game and if there was anythign wrong. I don't know what I said or did but it wasn't deliberate or even at her, but I clearly hit some buttons. she says stuff like, "no i'm not ok. dont call me names because of who i am and that i have better thigns to do than get fucked up i took great offence to it."
she's reffering to me setting up a night out for the whole team and I make a joke where we can drink away some brain cells. that comment had nothing to do with her. 
also, I had just signed on a new player on the team because some of the girls weren't showing up for the games. she messages me about it right away, and she's angry and upset. telling me to ask the team before i sign someone on. this is because mash claims she's had trouble with this chick harrasing her and says that if she sees her, she'll punch her. i don't like giving her want she wants just because she's emotional. i'm a bit dismissive with her, but i eventually tell her that i'll take the girl off the team because Mash was first and i dont want drama on the team. SHe's furious that I wasn't respectful about it and didn't do it right away, that i asked questions about she didn't want this girl on the team. 

Mash Potatoes has very intense and personal reactions to everything. 

Second(ish) run in; Mash Potatoes and Scuba Steve rock up to one of our games just to watch. Mash has said that she's resigned from the team because she wouldn't go if Bangers was still playing. Bangers and Mash had a mad falling out, they've had to get restraining orders on each other in the past, etc, and shit is hitting the fan again. There are really bad vibes from Scuba Steven and Mash Potatoes towards me. They heckle me and sneer at me when I'm near their side of court while I'm player. Mash sneers something like " I quit the team [because of Bangers and] because this chick thinks she's the boss". Scuba Steve is being uncharacteristically nasty with me, heckling me, sticking her finger up at me. Scuba Steve was coming onto me only a month ago, but she's over weight so i kept it friendly. I get the jist that Mash Potatoes hates the fact that I run things, - and to her credit, i wondered if I was being controlling with the team, but no one else had issues with me - and that Scuba Steve is deliberatley copying my managing role with team, as if to over throw me. I don't care if she's grows into a more alpha type person, that's awesome. She'd been learning from me for a few weeks before this even happened, and were really getting along. I don't talk to either of them much after the game or between quarters becaues I felt so uncomfortable. I chat with our team and i'm crazy over our new player, who's amazing at soccer. I ask this new chick about the other girls she said she could recruit, and I see Mash sneer at me because i'm taking charge and not asking Mash's permission or something. i'm not sure. she's pretty unstable, obviously, and hates the way i'm handling my role in the team. Am I too controlling by signing on new players onto the team without getting a group vote first? I think I should have asked the team. I didn't because they didn't all get a say who was on the team initially, and it was too much bureaucracy, but in hindsight, it would have been better form if I had asked the team first.

Mash potatoes has also caused drama by saying caustic things in the group fb chat, that was getting aggressive at teh girls who weren't showing up. it turned into a big drama until i cut that short with positivity and by calming one of teh reactive girls down. it turned into a big love fest instead. :)

Third run in last night:

i see her at a dance party in which most of the team attend, and i beckon her over, get her to pull up a chair and to talk with me. She told me about the story of the falling out between her and Bangers. I'm like, "but are you ok?" knowing that she's angry with me, and upset at things n such. she's almost kind of shaking. She has a lot of hate on her face. I tell her to come back to team because I knew she really wanted to come back, which i now regret. She then goes on in a way in that was threatening and full of cold rage, saying that i rub people (meaning her, obviously) the wrong way. that i need to take care of how i come across. that i was being (somethig negative) at the last game because i apparently hardly spoke to her and that she's not the only one that thought that (despite the fact they were both giving me shit).  she tells me that no matter how tired i am (reffering to me being clearly dead on legs at teh last game), that i come over and say hi to her. That if i ever talk badly about her to anyone, she'll always know, and that I can't ever do it. etc, etc. 
IMO, this is where she crosses that border into controlling psychobitch territory. i've never seen so much hate on someones face. i don't get it. but we talked it out a bit and she hugged me goodbye when she left the venue. I should have pushed her bullshit back onto her that night, but i wasn't sure enough of my boundaries at the time, buying too much into what she was projecting. urgh. 

my first idea was to talk it out with her at the next game. but maybe i need to have her exiled so she doesn't come back to hassle me or anyone else.

i can put something like this into the fb group chat but it seems weak to me. i don't even like it. 

Mash, you came at me in a threatening and controlling way on saturday night. And you have been aggressive and bitchy towards me in the recent past. You've brought drama into the team on a number of occasions, and it's going to keep happening as long as you're here. If you have an issue with the way things are, you aren't going to enjoy the rest of your time on the team, because you can't bully me or control me. it's better for everyone if you play a different sport - a solitary one.