I'm not sure if this will be of any help to you or not but thought I would go ahead and write.
John Rowlett and Lockey Brown were married April 23, 1791 in Chesterfield Co., Va. by Rev. John Cameron, Rector of Bristol Parish, Episcopal Church. This infomation is from Chest. Co., Va. Marriages and "Cumberland Parish, by Bell".
Lockey Brown,widow of John Rowlett, married Robert Partin March 14,1808 in Chesterfield Co. This is from Chest. Co., Va. Mariages. Surety was Herbert Brown. My guess would be that Joel and Herbert are brothers to Lockey. No proof though.
I know of no children by John and Lockey. Since none were mentioned in his estate settlement, I doubt if there were any. If so, they would more than likely be living in the home with Robert and Lockey in 1810. Since Robert and Lockey married in 1808, any children older than two would probably be John's and Lockey's.
I'm not sure if I have anything on more on Lockey and Robert or not but while I am documenting my work if I run across anything else I will send to you.