How can I secretly donate my money held by my mother in another country, so that I may be among those whom Allah shades with His shade on a day when there is no shade but His, while it is necessary to inform her of the amount of money?

If it is possible to give secret charity without your mother's knowledge, that is better. If not, then inform your mother of the amount of money, requesting her to keep it secret. Perhaps Allah will include the giver of charity among those whom He shades with His shade. The Prophet, peace and blessings be upon him, said: "Indeed, actions are by intentions."