Hi Everybody, Lawyers and experts, I was just curious if anybody know the answer to this,

the story is my sister in law had a step sister, who passed away and left her a 21% stack in a commercial building, the step sisters family is pretty crappy not paying her fair market, rent they said they spend money on this on that, you know typical stuff, so she wants them to buy her out property is worth $1,100,000, so her stake is worth $231,000, since its in a limited family partnership she cant sell to external people right ?, so the people were going to offer her $145,000 a little more then half, that she was heavily considering, since they are a royal pain to deal with and getting anything out of them was already a win, so now her lawyer switch sides and works for her step sisters family against her and send her letter saying that she need to find other counsel that that lawyer she had works now for them and the offer is $90,000 which is crazy, she dosent want me to get involved or use my lawyers, but I was thinking can you sell a investor a promissory note or something like that since he will be getting money her cut of the rent is $11,550 annually that's like 4.5% return, if she were o sell to a investor her stake for the original $145,000 making the investor like 8% on his money is this possible o sell if yes how, hope it made since, I am not very good at the lawyers stuff.