The cycle ends when she decides to end it. There's no other way. Although she won't realize the power and ability she has, to make this change.
She needs to want to make changes in her life.
Even if it's something like accepting they're incompatible because she wants to be with someone who showers and cleans their teeth and he doesn't want to do these things. That alone is enough reason to break off a relationship.
Same goes for things like accepting that whilst we all have opinions on how other people look, polite people don't voice those opinions. So it's not about whether he's right and she's ugly or not, or whether she makes enough effort or not, or whether anybody else would find her attractive or if she'd be single forever. It's about whether she wants to be with someone who lacks basic manners and says rude things.
It's accepting relationship should be about kindness, so it doesn't matter if they have a different "sense of humour" (we know it's abuse but she can't see it) and thinks pushing people is funny. It's about telling someone that being pushed hurts, so if that person loves you why would they do something to hurt you? Even if the reason you're hurt is because you're "too sensitive" (or whatever bullshit he tells her). That becomes irrelevant because regardless of why it hurts, why would a person do something to deliberately hurt the person they love? It's not an accidental thing when she's already told him it hurts her, he can't then claim he didn't realize or didn't mean it. If someone does that it means they're not a nice person and don't love her. Does she believe it's ok to hurt people at all? Especially people you love? Does she believe nice people do this? No? But he does think it's ok. So they don't share the same values then. It's another fundamental incompatibility.
These are the conversations to have to start to make her see sense.
She needs solo therapy (definitely not couples therapy) with someone who isn't focussed on keeping families together. She needs to be involved with women's welfare charities, to be around people who will say hold up, that's not ok behaviour, that's not right, you shouldn't be treated like that nobody should (it's not enough to say I wouldn't put up with it, she's not you and she has been trained to put up with it). So she can literally see there's another way, because she's meeting people who are living it and how people can thrive when they're away from the toxic situation, hear them say they've experienced same as her and tried everything but the only thing that made it stop was leaving the relationship. Somewhere she can learn about the cycle of abuse and start to recognise that she's in it.
Unless she has a sudden realisation one day that anything is better than what she currently has and leaves for that reason, even if it might mean she starves homeless and friendless in the gutter (or whatever he's been saying), then slowly opening her eyes to it is the only way.
Think of it as sort of being addicted to drama. That's her comfort zone, her "normal". She doesn't want to step into the unknown, it seems easier to stay in denial and tell herself everything is fine. Like any addict she's not going to change because someone else wants her to (although obviously she's changed for him, to avoid his punishments as much as possible, even if she doesn't realize any of that). She has to want to change for herself, she has to be ready for change and strong enough to go through with it (cut him out so he can't wheedle his way back into her life and so her head can clear and she can start to heal). Many people never are ready. Many try and fail and return to the abusive relationship multiple times, before achieving the success of escaping for good.