This is all happening to my best friend and not myself.
So for some background my myself and two others have been friends with my best friend, let's call her Sarah, for almost 4 years now, though it feels much more than that. The 4 of us have been pretty much inseparable since day 1 and are well acquainted with each others family members. I live in a country where you don't move out at the age of 18, and stay with your parnets who pay for your living and school until basically you're married. And cousin marriages are pretty common here and are not considered bad so please don't say anything about it being incest, while I myself am aware of the dangers, cousin marriages are as common as the cold and there's nothing we can really do about it. Now that that's all out of the way let's get on to the story.
So this all started a few months ago before coronavirus hadn't spread its roots and we were still going to school, the virus wasn't in our country at the time. My friend Sarah brought up that her parnets are trying to convince her to marry her cousin, who is 10 years older than her because it would better than the ties between their families and becuase she couldnt get a better proposal than this as 'they would take care of her and she would be able to do whatever she wants'
She said no because she didn't like that cousin and said he wasn't a good person and we left it at that because we didn't think it would go further. So a few months later her after the pandemic started and we were all in quarantine, her parents brought it up again but with more force. They insisted she would not get a better proposal and even went as far as to say 'you won't find anyone better because you're not pretty and you're fat' and yes im still mind blown that her parents would say that to her.
So long story short, her parents were emotionally blackmailing her to go through with it because 'they knew what's best for her' and they had rebuttals for all the arguments she presented and said that they were 'very disappointed in her' at this point I even contacted her older sister [23F] and when we all talked to her at first, she said that this was what was best for her and agreed that she wouldn't find a better proposal than this even though she herself is engaged with someone she loves. And her oldest sister [24F] couldn't really care less. somehow she got her point across that she doenst want to and they left her alone about it and again, we left it at that.
And now finally we are at recent events. Sarah was being forced into going to another city with her family to visit her cousin and his family. She of course didn't want to go, but despite making every excuse she could think of, had to go. So she went and was enjoying herself as it was eid; a festival we celebrate in islam, when her parents tell her she's getting engaged tomorrow. We got so worried and told her to her parents she doenst want to get engaged without her best friends being there for it so that she could avoid it for now and try to get out of it later. She as being emotionally blackmailed despite all her pleas and at one point her parents threatened to take her phone away so that she couldn't contact us and called us bad influences. We phoned her mom and tried to convince her not to go through with it and to at least do it over here so that we can come and she told us not to worry because they would do it at their home.
They seemed to be convinced at that and now they are back home, but her parents got angry at the fact that we (my friends and I) called them and they threatened that they would take her out of a levels and put her into our countries education system which is called fsc. They also said they would take away her phone. So now she is pleading with us to not contact anyone from her family because her parnets are really angry and even cancelled our plan to come to her house to convince her parnets (none of us have corona and have been at home for 2 months now). We don't know what to do and how to help her anymore. What should we do?
Tl;dr: my best friend is being forced into an arranged marriage with her cousin 10 years older than her and if she refuses or we try to stop it, she's being threatened to have her phone taken away and being put into our countries education system instead of a levels.