So let's say it happened. Now you have $90,000 in an account with your US tax id. Suppose your family says to give $30k to your sister and $30k to your brother. If you give them this money in a single year, you are responsible to file a gift tax return. Unless of course you or they are married, in which case you could give twice as much, or even 4 times as much if you are both married, but that gets us into the weeds of the tax law.
You mentioned $16k. That's because the annual gift tax exclusion just went up $1000 to $16k for 2022. As long as you give $16k or less from any one taxpayer to any one taxpayer, you do not have to file the gift tax return....
You mentioned that the IRS might want to know how you got the money. One thing you can do is have a family member write you a letter. They can even have it notarized or witnessed, saying that where these funds came from and that they are not earned income for you, but rather a gift entrusted to you for your family's continuing benefit in these difficult circumstances.
However, the IRS is mainly concerned about collecting taxes, so they are more interested in who you send $10,000 or more to, not money arriving in their jurisdiction from somewhere else. It's the police who care about both ends :-). Documenting the transaction is a good first step for both. It would be more of a problem if you got the money from a "Nigerian prince" and you don't have family in Nigeria.
