Yes, in Islam it is permissible for girls to wear loose jeans with a loose shirt or a short loose dress as long as the basic principle of modesty is fulfilled.
The principle Islam sets is not a specific uniform, but satr and dignity. Clothing should:Cover the body decently, Not be revealing or skin-tight, Not be worn to display the body as an object of attraction
Islam focuses on purpose and effect, not on labels like jeans, kurta, abaya, or dress. These are cultural forms, not religious requirements.
Modesty in Islam is about zīnat (adornment) and intent, not fabric names. If the clothes are loose, respectful, and socially dignified, then they fall within what Islam allows.
If the clothing maintains dignity, does not expose the body, and is not meant to provoke attention, it is permissible.