What is the ruling on dealing with Egyptian Islamic banks, and what should I do to convince my mother of the permissibility of Mudarabah (profit-sharing) despite her not being convinced by it?

A mother's fear of the people of this time is well-founded due to the prevalence of deception. The existence of doubt regarding some Islamic banks, stemming from their incomplete adherence to Shariah guidelines, justifies her concern, but it does not mean that dealing with them is prohibited. One can investigate to find the most trustworthy among them. One should not do anything that angers the mother by giving money for speculative investment. Instead, it can be deposited with trustworthy Islamic banks. However, if the money is given to someone trustworthy for speculative investment, there is no sin in that.