JazakAllah khayr Ustadh. You mentioned: “The niqab shouldn’t show the eyebrows and cheeks, only the eyes show.” Sorry if I wasn’t clear, I wasn’t asking about the coverage of the niqab, but rather if it’s permissible to shape and beautify the eyebrows for the husband, since they’ll be covered.

Ustadh AbdulAziz al-Haqqan

If you mean pluck and shape the eyebrows, this is nams and it is forbidden by the very known hadeeth.