I will run the risk of incurring the wrath of the couple who administer this board by suggesting that your search for information here will be fruitless. Most visitors to these boards post and disappear, which is why you'll see so many long time lags (five years is not uncommon) in message board threads. Most visitors to this board are researching Southern families who are unrelated to the Brooks families of early New England. And most visitors, like you have done, mask their email address, which further obstructs easy and timely communication.
I administer the BROOKS and BROOKS-NE (Brooks families of New England) mailing lists at Rootsweb/Ancestry, and as such your posting was forwarded to me. I can tell you, on the basis of 15 years of monitoring this message board, that the number of people here researching Brooks lines descended from old New England is slim to none. (I know this because I reply to each one who posts a New England-related query, and do my best to lure them away to the BROOKS-NE mailing list, which connects 165 researchers of Brooks/New England families.)
Lydia Brooks was in what we call the Woburn line, descended from Henry/1 Brooks, the emigrant progenitor, born in England, died in Woburn, MA in 1683. We've done extensive Y-DNA testing of males in this line, though no mitrochondrial testing (which isn't really functional in a world of lists organized by male surnames).
I have two suggestions. (1), visit the Tributaries web site, www.tributaries.us
, which is focused on the 15 Brooks males known or suspected to have left progeny in America by 1700. (Among other things there, check out the DNA testing link.) (2), email me privately, email@example.com
, and I will happily exchange information with you on this family, as well as put you in touch with a gal who's spent years researching descendants of Zilpha Brooks/Eliakim Hamilton. Be advised that Lydia in all probability had an additional brother Luther, b. about 1763, husband of Miriam Gleason, who spent his entire life at New Marlborough.
As to your specific query concerning Indian ancestry, I've seen/heard nothing of the sort concerning the individuals you've named, and would be exceedingly suspicious of any such claim in the absence of proof. (Which needs to be much more that the typical family legend that Aunt Myrtle had black hair and black eyes "that could see right through you," as someone posted me two days ago, wanting to claim Mohawk ancestry.) The surname of Sarah, wife of Jabez/5 Brooks, is unknown to date. Jabez probably married her in or around Killingly.
Hope to hear from you!