If you've stopped donating to Oxfam, consider donating to these charities
or https://wycegambia.org/
The first is UK based. The other is based in The Gambia. They work closely together.
My Gambian friend is sponsored by WYCE to train as a teacher. She is doing a 3 year course at The Gambia College to be a secondary school teacher of English and SES.
WYCE also work in other areas, including with another uk charity called Re-Cycle, donating preloved bikes to children to cycle to school.