I usually answer GenForum Chamberlain queries, on behalf of the World Chamberlain Genealogical Society, but spotted yours here, and decided to check it out.IGI records (Mormon online site), list Sarah Jane Bradbury, b. 9 Apr 1833, Minot, Androscoggin Co., ME, as one of four children of Jacob & Rachel (Chamberlain) Bradbury, who were married 1820, Auburn, ME, with 4 children listed there between 1822 and 1839.There is also an IGI listing for Jacob & Mary (Chamberlain) Bradbury [as you have it], but this seems to be in error.I've identified Rachel(6) Chamberlain, b. 1797, Dracut, MA, as one of 7 children of Silas(5) & Susanna (Jones) Chamberlain [Joseph(4) Jr., Joseph(3), Thomas(2), Thomas(1)], who came from Dracut, MA to Minot, ME sometime before 1810.Jacob Bradbury was previously married, 16 Oct 1810, in Minot, ME, to Rachel's sister, Sally(6) Chamberlain, b. 1791, Dracut, MA, with two children listed by this marriage, born in Minot in 1811 & 1813.Silas(5) Chamberlain is listed in the 1810 Census at Minot, Cumberland Co., ME [later in Androscoggin Co.).A brother of Sally & Rachel, Aaron Jones(6) Chamberlain, is listed in Minot from 1820-1840, then in Auburn, Cumberland Co., ME, in 1850 & 1860, and the eldest sibling in this family, Joseph C.(6) Chamberlain, is listed at Minot 1820-1840.So, this Chamberlain family is well represented in the Minot/Auburn area over a long period of time, and you should be able to obtain considerable information on them in records there and verify this information, if you wish.
I have no information about Sarah Jane Bradbury's marriage or descendants, which was the subject of your posting, but I hope this Chamberlain information is of interest to you.