Immigration Law Questions? Ask an Immigration Lawyer.
Can I ask if you have met her in person before?
Unfortunately, it is likely that this is a scam. It is typical for scammers to look for someone and then after they are hooked, to pretend like they are in trouble and they need a certain amount of money paid to get them out of trouble.
See Message 5 here for a similar situation:
Unfortunately, as you can see, this scenario is all too common. You are not the first person here to ask about this kind of situation. So based on the circumstances you have relayed, it sounds like this person is trying to scam you out of money to pay this "fine."
I'm not saying that a real person is not on the other end of your conversations...I'm just saying that this claim about the "fine" is most likely not real. Particularly as she is from Ghana, where a huge number of these scams originate. I'm sorry, but this is pretty textbook. They don't just hold people and force them to pay a fine. There are legal processes that occur.
That is probably a good idea. The immigration officer is likely in on the scam as well. I would suggest calling the embassy in Ghana so they can look into these individuals and check them out for you before you send any money.