Four girls named Boyd attended the Mordecai school:
Christian Blair Boyd was there for both sessions in 1811.
Eleanor Boyd of Mecklenburg Co., VA, was there from mid-1815 to the end of 1817; the name Mrs. Elizabeth Boyd is associated with her account.
Jane Boyd was at the school for one session, in the latter half of 1815, with the name William Boyd associated with her account.
Virginia Boyd attended in 1816.
Just as an illustration of how complicated Southern family naming habits could get, the Christian Blair Boyd (1801-1860) above was born in Warren Co., daughter of Panthea Burwell and Col. John Boyd; but she had a double-cousin also named Christian Blair Boyd (1816-1868); his mother was Panthea's sister, and his father was Col. John's brother. (We'll be getting to the Burwell girls soon, but the Boyd and Burwell families are fairly entwined, so hold on tight.) The female Christian Blair Boyd married John T. Garland in 1819, and they lived in Lunenburg VA; they had three children (1821, 1824, and 1826). The youngest died in infancy in 1827; Christian would also bury her only daughter, Panthea Ann Garland, in 1848. Her son John Richard Garland lived to 1899, and became a prominent judge and mill owner in Lunenburg. Christian was widowed young, in 1828, and she remarried in 1832, apparently to a kinsman of her late husband: David S. Garland (c1787-c1865).
Christian Blair Boyd didn't have any sisters, but it looks like the other Boyds were probably her cousins. Eleanor Boyd (1801-1833) of Mecklenburg Co. VA, daughter of David Boyd (1778-1815) and Elizabeth Ott Durell Boyd (1783-1835) seems to have been sent to school in the event of her father's death in the same year, which is why her widowed mother "Mrs. Elizabeth Boyd" is the adult on the account. Eleanor had a sister Virginia (b. 1805), who might well be the Virginia Boyd who attended the school; she married a Richard Pryor in 1821, and moved to Hempstead Co., Arkansas with him. David Boyd's brother was Col John Richard Boyd, so these girls would be first cousins to Christian Blair Boyd.
The Boyd men also had a brother William (1767-1834). He married Frances Bullock in 1791, and their second daughter was.... Jane Boyd (1798-1835). Good chance she's the fourth Boyd. Jane Boyd married Dr. Charles Lewis Read (1794-1869), in 1816, and moved to Granville County, NC. She had ten children before she died at age 37 (in childbirth).
So this is the scenario:
Three Boyd brothers with daughters around the same age; the eldest girl, Christian, went off to the Mordecai school for couple sessions in 1811; a few years later, when brother David Boyd dies, her his daughter Eleanor Boyd and her cousin Jane are also sent to the school, and soon Eleanor's little sister Virginia joins them.