Firstly, there is the very important narrative given by Nathan Knoles in 1887. He mentions the surname REED three times:

1	David left Georgia about 1808 and settled in Tennessee for a year or so, when he moved to Kentucky, where he remained until 1815, when he came to Indiana with Reuben Reed.
2	James Knoles, my brother, married Annie Reed. They raised three sons and six daughters, named: Resa, who died in Mount Vernon, Indiana; a year or two since; Alberry, whose address is Bagley, Iowa; and Barnet, whose address in Long Pine, Neb.; Nancy married Jesse Douglas and is living near Fort Branch; Patience is dead; Sallie is dead; Comfort married Jacob Spore and is dead; Kittie married James Boren and is living near Fort Branch; Matilda married John Montgomery and is living near Forth Branch.
3	Brother Jesse married Elizabeth Reed. They raised nine children, four boys and five girls, named: Eli, Reuben, Jesse, Sam, Emily, Lizam Patsy, Lousilla, and Elizabeth. Eli is living in Missouri. Reuben is dead. He raised a family in Illinois. Jesse raised a family and in crossing a river somewhere in Kansas some years ago was drowned. Emily is living somewhere in Illinois; Liza lives near her. Patsy raised a family and died some years ago. Lousilla and Elizabeth are dead. I don't know whether they left families or not. Brother Jesse moved to Illinois and died there more than twenty years ago.

Secondly (and see above), Jesse KNOWLES and his wife, Elizabeth (REED) Knowles named one of their sons "Reuben Reed Knowles.

I have always been of the opinion that Annie REED and Elizabeth REED were close relations, and probably sisters. Jesse Marvel Knowles married Elizabeth REED 09 APR 1807, in Greene County, Georgia. This is the same place, and only a little more than a year after the marriage of James KNOWLES to Annie REED.

So, when taken together, I think it is not a poor guess to suggest that both Elizabeth and Annie are daughters of Reuben Reed. Unfortunately, I have never found any information on Reuben Reed other than what is in the Nathan Knoles narrative.

I think it should also be pointed out who the father of Annie and Elizabeth can NOT be. There are some suggestions online that they are the daughters of one George Reed (12 NOV 1760 - 15 MAY 1815). This really cannot be the case. Firstly, this Elizabeth Reed (daughter of George Reed) seems to have married John Wright Randleman, not Jesse Marvel Knowles. Secondly, this George Reed had two daughters who could have been referred to as "Annie". There was Hannah Reed and Ann Reed. Clearly, neither of these could be the wife of James Knowles, as Ann REED was born 18 MAR 1808 (viz., AFTER her supposed marriage date), and Hannah REED fares not much better in this respect, as she was born 10 MAR 1797. This would require her to have married just after her NINTH birthday, which is rather impossibly young, even by the standards of those days. Furthermore, the dates of birth are directly from the Bible of George Reed, and thus are not negotiable.

Continuing the onomastic evidence, I note that Jesse Marvel Knowles and Elizabeth Reed are said to have had the following children:
Polly Owen Knowles, born 26 MAY 1810
Reuben Reed Knowles, born 28 MAR 1812
Eli Knowles, born JAN 1814
Jesse Marvel Knowles, born 18 AUG 1816
Emily Knowles, born 30 OCT 1818
Samuel Hamilton Knowles, born 19 MAR 1821
Eliza Ann Knowles, born 29 JUN 1823
Patsy Jane Knowles, born 19 OCT 1825
Martha Lucilla Knowles, born 11 DEC 1830
Charles S. Knowles, born 13 JAN 1833
Elizabeth Knowles, born 02 FEB 1835
George Knowles, born about 1841

I cannot vouch for any of these claims, but I can say that they generally agree well with the Nathan Knowles narrative (see above). I have found some other records which indicate that this list of children is at least generally correct. The reason I bring it up here is this - Jesse Marvel Knowles is brother of "my" James R. Knowles, and I believe Elizabeth Reed is sister to "my" Annie Reed, thus any naming pattern which hints at ancestral surnames for them (i.e., Jesse and Elizabeth) should apply equally well to me. So I am now trying to find links between KNOWLES AND/OR REED and OWEN, REED (of course), MARVEL (which connection is known, at least on one count), and HAMILTON.

Similarly, James R. Knowles and Annie (REED) Knowles had (among others) children named Alberry and Barnet (see Nathan Knowles narrative, above; "Barnet" is probably William Barnett Knowles). So I would also be interested to find connections between and among those families.

About all I can say about my Annie Reed is that she seems to have been born in North Carolina. I have been trying to find the 1880 census records for the children of Annie and Elizabeth to see where they will claim their mothers were born. Rhesa Knowles 1880 census shows her as being born evidently in North Carolina. Marticia (KNOWLES) Montgomery (called "Matilda" in the Nathan Knowles narrative) similarly seemed to indicate that her mother was born in North Carolina. But there is not perfect agreement. The entry of Nancy (KNOWLES) Douglas shows both of her parents born in Tennessee, which is fairly interesting in its own right. And Kittie (KNOWLES) Boren says her parents were both born in Georgia. Finally, if I have the right entry for Barnet Knowles (and I really may NOT), his 1900 census entry seems to say his father was born in North Carolina and his mother born in South Carolina. This last seems pretty suspect to me. But the others seem pretty reasonable, given the other information; at least there is known Georgia and Tennessee habitation for the families.

My line comes from Annie (REED) Knowles' daughter, Comfort (KNOWLES) Spore. I have her death certificate around here somewhere. When I uncover it again, I will scan it and put it here. On it is handwritten in the top margin, "Father: Jas. Knowles Mother: Annie Reed". I don't know who wrote that on the certificate (viz., whether it is original to the certificate or added later), as I received it at least second-hand.