May a family member request a ballot on behalf of an UOCAVA voter?

Relatives of a UOCAVA voter may complete an application on behalf of a UOCAVA voter using SOS Form 11-E (Fillable PDF),

Eligible family members: Relatives include spouse, father, mother, father-in-law, mother-in-law, grandfather, grandmother, brother or sister of the whole blood or half blood, son, daughter, adopting parent, adopted child, stepparent, stepchild, daughter-in-law, son-in-law, uncle, aunt, nephew, or niece of such a person. R.C. 3511.02(C)