ok checking the 1840 Union Co SC census I see only two possible hh in which your Dicey could be as a GLenn.Elizabeth Glenn is, I believe, Elixabeth Wright Glenn, widow of WIlliam Coleman Glenn...in her hh is a female age 15-20 and male age 20-30.I can identify who these two are but this line is well documented and I have a book about them to check also...William Coleman Glenn died in 1827 Date: 1827/05/25
Description: GLENN, WILLIAM C. OF UNION DISTRICT, WILL TYPESCRIPT (MSS WILL: BOOK B, PAGE 124; ESTATE PACKET: BOX 15, PKG 23) (3 FRAMES).
Names Indexed: GLENN, WILLIAM C./GLENN, SARAH C./COLEMAN, ELIZABEATH/MAYS, JAMES/GLENN, THOMAS A./GLENN, JANE S. C./GLENN, ELIZABEATH/CHARITY (SLAVE)/HARDY, HENRY/HAWKINS, NATHAN/SARTOR, JOHN/SARTOR, WILLIAM P./TEAGLE, RICHARD/SELBY, HAWKER/PREWIT, DAVID/ANDERSON, ELIJAH/ROGERS, JOHN/DARBY/GILBERT (SLAVE)/AGG DICE (SLAVE)/JOE (SLAVE)/JOHN (SLAVE)/BILL (SLAVE)/GEORGE (SLAVE)/ATTERSON, SAMUEL/GLENN, SPILLSBY/GLENN, JAMES B./GLENN, LUCY/HANAH (SLAVE)/IVY, SAMUEL/BOWKER, ACHILLES/DAVID (SLAVE)/RACHEL (SLAVE)/TEMPY (SLAVE)/BOWKER, ELIZABEATH W. G. A./MOSES (SLAVE)/BOWKER, THOMAS/DICE (SLAVE)/COLEMAN, NATHAN/PHILLIS (SLAVE)/MAYES, JAMES/ANNA (SLAVE)/ALCE (SLAVE)/GLENN, PATSEY/LIZY (SLAVE)/JIM (SLAVE)/GLENN, NATHAN/GLENN, WILLIAM W.
Locations: UNION DISTRICT/TYGER RIVER
This is not proof your Dicey is there but it is a place to look.I would want to get the records of William and of his wife Elizabeth.