Thanks for the replies

God, I don't know. She's your sister afterall so you can't turn away from her for (maybe) a moment's silliness. Try to find out why she's refusing to leave nigeria; ask her, ask relatives you know you can trust, etc. There's probably more to the situation than you can see. Yeah, I know we sometimes have to be cruel to be kind and let our loved ones suffer a bit so they can learn a lesson that will profit them in future. But weigh the options carefully. Will she really learn by being ignored? Try to find out whether she's been negatively-influenced by friends or ill-scheming relatives. Don't give up so easily on her.

On another note, does she trust you? Are you guys really close? Because you being half-siblings may mean you don't trust each other so she may be having doubts as to what you want her to do overseas. I mean, what with all these trafficking and all. So find out what she is afraid of and decide what is in HER best interest.

This is more than meets the eye. What sane girl in Nigeria would refuse an offer to study abroad, especially the US? And when you say 10k, is that in dollars? Sorry to say but that girl has something up her sleeve if she's asking you for 10k in dollars. Don't let her milk you. Make out a day and call her and ask her what her plans are for the future. You can't be there sweating it while she wants to live it up in Nigeria. She's your sister, so obviously, she's your first priority, so she has the right of first refusal so to say. Don't give in to any pressure to keep sending money to her. She may play the emotional card but what you are offering her is more than anyone can do. Still speak to her and see how it goes. Also, like the last poster said, try to make some enquiries. She might be influenced by some scheming people who see her as their meal ticket through you. I presume she's young which means she's impressionable.

Its very difficult to deduce the reason for your sister's action but I can say you have a good heart.Sorry to be too nosey but if your mum died at the age of 39 and you already have a business of your own (assuming you're in your mid twenties) you have been really blessed and elevated.Is it your friend's desire to go abroad to further his studies? If yes then you can do your bit to assist him bearing in mind the limit to which you can help.Warning!! Consider yourself and your fiancé as your best friend.I understand how this friend can be but speaking out of context,perhaps make him a ver close friend.Your friend I will consider a greater potential than your sister in many ways you are aware of,your sister on the other hand doesn't sound positive about going abroad hence she's happy with her life.As the elder you won't cease to be more abound in knowledge keep looking out and after your sister until she refuses or reacts negatively to your favours.
In my opinion assisting your friend going abroad could turn out well for you but your sister? Let her be and provide as decent as you can for her.Also speak to her and share her world.It is no joke for young women in Nigeria especially without one of the parents and no sibling.She can turn turn a new leaf faster than acid burns.
As for that cock-up of Uncle's in-law.Uncle is a man and can obviously handle his business.I won't blink if I were you.All you have is your sister,this friend and your partner.

There's nothing new under the sun,do your thing.

Thanks for the comments till now

@stranger
I am not strange to her we grew up together at my mom side and because her dad did got involve with another woman that later gave him 4 other kids .The things i guess is going on there is that people are trying to keep her over there so she can be given them western union I don't traffic no human ,animal drugs or whatever lol

@annamaria 10k naira.

@kaestro  Yes i spoke with my friend and he is willing to leave the country.

Are u saying now that u wanna bring ur sister into the country and she doesnt wanna come?
Am sorry i dont really understand.