Let's look at what we should expect to find for Nathan Bodie, Jr. in 1830. We would expect to see at least 2 sons under the age of 5 (Jesse Pitts Bodie was born in 1826, and Andrew Jackson Boddie was born in 1828); Nathan himself at the age of 26; possibly no daughters; and Nathan's wife, Mary Edna "Edney" Eidson, who would be 24.
When we search the Edgefield District census for 1830, we find two households headed by a "Nathan Body". The head of the one listed between Isaac Crouch and William Whittle is in his 60s (too old to be Nathan Bodie, Jr., but the right age for Nathan Bodie, Sr.), but the head of the one listed next to W. Deloach is in his 20s. If we assume that this is Nathan Bodie, Jr.'s household, then we have:
3 males under 5
1 male 15-20
1 male 20-30 (Nathan Bodie, Jr.)
1 female 20-30 (Mary Edna Eidson Bodie)
The extra male under 5 may be a son who died prior to the 1840 census. The male born between about 1810 and 1815 may be a younger brother to Nathan or to Mary Edna. So far as I know, Nathan's only younger brother, Joseph Bodie, was born in 1808, so Joseph would be too old. Mary Edna may have had at least 4 younger brothers: William Wiley Eidson, born in 1809; Mahlon Eidson, born before 1819; James Russell Eidson, born in 1821; and Allen Eidson, born about 1832. So Mahlon remains a possibility. It will be necessary to find the household for Mary Edna's parents and some of her siblings to rule out Mahlon living with those other households.