Probable marriage based on date, names.
From marriage records, it appears Ibzan first married Polly and later her sister Ursley.
Polly BROOKS and Ibzan RICE were married on 8 December 1818 in Caswell County, North Carolina.43 Ibzan RICE, son of Hezekiah RICE and Mary BULLOCK, was born circa 1768 in Caswell County, North Carolina. He died in 1847 at the age of 79 in Caswell County, North Carolina.
Caswell Co NC 1830 Census, p.311 Ibzan had 2m -5, 1m 5-10, 1m 60-70 [Ibzan?], 1f -5, 2f 5-10, 1f 20-30, 1f 30-40. His wife would have been Ursley by this time and they were living next door to her mother.