I see no indication that Edwin had any sons.He married Ardella in 1881 and she only had one child, so none were lost in the census gap.There also is no Sarah/Sally Ann.Be sure you are not mixing two families together.
1850 Callaway, MO Hubbard, Frances 40 VA Edwin 12 MO Albert 8 MO
1840 Danville, Montgomery Co. MO (next county over) Hubbard, Albert Males 1<5 and 1 20-29 Females 1 20-29
Albert G. Hubbard married Frances A. Austin 3/18/1835 in Callaway Co. MO.
Frances Hubbard 60 (female) is living with Edwin & his family in 1870.
There is no indication that Edwin had any siblings other than Albert, who does not appear after the 1850 census.