Partnership investment, a quarter of the income generated by this investment is hers. If interest is charged, it means paying interest on schedule every month. There is no income from sub-investment. Whether it is a loss or a profit, she only collects interest as agreed.
This investment shares a quarter of the risk. If it is a loss, she will also lose money.
Paying interest is like a bank loan. Whether you make money or lose money,
Shareholders shall bear the investment risks in proportion and share the investment income.