1850 census of Bath Co., Ky, division 2, enumerated 31 July, lists on p. 33 as family #229:
James Wells, 49, farmer; Rebecca, 27; Joseph, 21; William, 19; James, 16; Alexander, 14; Elizabeth, 10; Mary, 7; Thomas, 5; Robert, 4; Benjamin, 2. Joseph Jones, 23, laborer.

The older children are from James’ first marriage, to Polly Becraft. I do not know precisely which, though, because I cannot find a record of James’ second marriage. Tentatively, I am allocating Elizabeth on up to Polly, and Mary on down to Rebecca. It seems likely that Mary goes with Rebecca, since in the 1860 census (see below), James is the only one who is listed out of birth order. And Alexander is too old to be a son of Rebecca. That mainly leaves Elizabeth as the one whose mother is uncertain.

1860 census of Bath Co., Ky, Owingsville P.O., enumerated 4 July, lists on p. 93 as family #678:
James Wells, 59, farmer; Rebecca, 40; Mary, 17; Thomas, 15; Benjamin, 12; Susan, 8; James, 26. All born in Kentucky.

1870 census of Bath Co., Ky, Mudlick precinct, Olympian Springs P.O., enumerated 24 Aug, lists on pp. 44-45 as family #323/326:
Wells, James, farmer; Rebecca, 48; Thomas, 26; Susan, 18; John, 12; Elizabeth, 10.

John and Elizabeth are probably grandchildren - John because he does not appear with the family in 1860, and Elizabeth because James had a daughter Elizabeth born about 1840.

1880 census of Bath Co., Ky, Polksville precinct, enumerated 12 June, lists on p. 17 as family #154/156:
Wells, Alexander, 64, farmer, b. Ky Penn Ky; Gracy, 59, wife, b. Ky Penn N.C.; Beckey Wells, 56, boarder, widowed, b. Ky Penn Ky; Susan, 26, dau, single, b. Ky Ky Ky.

This Alexander Wells is not the one who was the son of James Wells and Polly Becraft, since he would only be about 44.

Bath Co., Ky marriage book 1 records the marriage on 11 Jan 1824 of James Wells and Polly Becraft, bond surety by Wm Becraft.