How do I help my friend?

So, last month my friend of four years revealed to me that her mother was abusive. She never mentioned it before because she was embarrassed about it. And just in the last two months, her mom has done awful things.

About 5 weeks ago, my friend woke up in a bad mood because her mom basically spent the whole of the night before making her feel bad about her body weight, calling her lazy and a piece of sh!t because she was going to prom. She was looking for her water bottle and asked her sister where it was because she couldn't find it. She didn't hear her the first time and asked her again, but her sister just told her to look for it and pushed her & yelled at her to get out of her way. My friend pushed her back, but heard the doorbell ring and tried to leave because her ride was there (her boyfriend). Her mom came down the stairs and cursed my friend out. my friend tried to ecplain the situation, but her mom shoved her up against the door and hit her for trying to "talk back". Since my friend's house has paper thin walls, she was afraid her boyfriend heard so she texted him to leave and fled to the laundry room. At this point, my friend has no ride to school, but her mom followed her in to the room, where she was crying, and threaten to hurt her or send her to jail if she didn't get up and go to school. When she tried to explain herself, her mom calls her disrepectful and other names. She wants her to get up, but of course my friend is hysterical at this point and doesn't want to. So, her mom grabbed her by the hair and dragged her in to the living room where she proceeded to hit her with a cake spatula. Her mom then left her sobbing, threatening to also take away all her stuff.

Two days after that, she messaged me telling me that her mom abused her again. During driving lesson, her mom was yelling at her for her "poor driving", and whenever she reacts to the yelling (while she is trying to drive no less!), her mom takes it as validation to scream and curse at her. When they got home, her mom continue to call her names and even told her that "your virgin @ss should be taken and raped" and threatened again (as with every argument) to call the police on my friend. She confessed that now she's eating and sleeping less and less, and that after that blowout she retreated to her room and tried to work on an essay while hungry. And then later she tried to kinda blow it off because her mom apologized and hugged her.

Another time her mom shoved her into a counter ans slapped her so hard her glasses came off. Apparently she had "gotten too mouthy"

Just last week, her mother verbally abused the younger sister for having color guard practice one week throughout the summer. Made her cry, so she ran up to her room, where their mom followed her and proceeded to mock her for crying. My friend tried to intervene and tell her mom that is wasn't right to yelled at her sister for it. Her mother responded by taking a bottle of febreeze and spraying her with it, saying that she's a dog and smells like one.

And a few days ago, her mom berated her again over her driving skills because she was a little over the speed limit. She made her cry and said that she'd never let her drive again. When they got hom, her mom shoved her to the ground and grabbed her by her neck and said "I brought you into this world, I can take you out of it."

I'm at a loss. Every step of the way I have encouraged her to tell our guidance counselor, to get help. Repeatedly she has pushed it off. She's told me it's hard, and I understand that, I'm just so afraid and I have such mixed feelings about everything. Like, we're going to college soon and her parents have threatened before to not help pay if she doens't do what they say, and she didn't get a lot in the way of financial aid (all she got was a $6,000 loan from the school in addtion to money from the pell grant and the two federal loans and the college we're going to is expensive). I'm afraid now that since our counselor is a mandated reporter that my friend won't be able to come because her parents will be reported and will withdrawn any financial help. I'm doubly afraid that CPS won't do anything because my friend and her sister are teens, and her youngest refuses to acknowledge that her mother is abusive (partially because my friend constantly intervenes), and my friend has never had to go to the hospital due to the abuse (to my knowledge). I'm also afraid that she won't tell all the details of her abuse because there is a huge difference between "my mother hits me sometimes" and "my mother has threatened to hurt me and has shoved me and slapped me so hard,s he knocked off my glasses.

She promised me that if she continues to push this off and doesn't talk to her by this Wednesday (this is our last week of school btw) that she would give me full rights to talk our counselor in her stead. And I just. I feel lost. Is it really okay for me to talk to her? Is this really the best decision? Should we take the risk of phoning it in and nothing happening except her mom becoming more violent when she discovers the report? Or should be wait until they've paid for the first semester and pray that her mom doesn't snap and do her serious injury? (for the record, my friend has said that her mom has been abusive (and came from incredibly abusive parents) since my friend was young, but wasn't so violent and phsyically abusive until recently