1)Baby bird cannot fly. Their mother has to feed \bf\underline{them}them
2. Vijay likes riding my bicycle. I sometimes lend \bf\underline{it}it to \bf\underline{him}him
3. Sooraj and I are brothers. \bf\underline{we\:both}weboth share the same bedroom.
4. Ravina isn't well. Dad is taking to the doctor. (No personal pronouns required)
5. My sister is a teacher. \bf\underline{She}She teaches Maths.