Erica Howton funny you should mention this! I was just reading up on interracial marriage in the early Virginia colony, and was surprised at the results.
Several scholarly sources report that there were cultural factors in both communities that worked strongly against it. This thesis doesn't mention marriage but talks about the general distrust and hostility between the two communities, which ramped up significantly on the English side after the massacre of 1622 and only got worse after the massacre of 1644: https://scholarworks.wm.edu/cgi/viewcontent.cgi?article=5814&co... The violence was a two-way street, with plenty of English attacks on Native villages. After 1646 there was basically an apartheid system in place: the English assigned some land to the Native population and didn't allow them on English land except in very limited circumstances. The atmosphere in the 1630s (when Pettus and Ka-Okee supposedly married) wasn't conducive to marriage-making.
This article is all about the cultural factors that worked against interracial marriage and even unmarried sex: https://www.jstor.org/stable/4248940?seq=1#metadata_info_tab_contents It talks about logging in through a school or library, but that's not necessary. You can sign up for a private JSTOR account and read it for free. It may take some experimental button-pushing to figure out how to open the full article.
This link says that there are only three recorded Anglo-Powhatan marriages in 17th century Virginia: https://encyclopediavirginia.org/entries/marriage-in-early-virginia... One of these was the marriage between John Rolfe and Pocahontas, which was basically a political alliance that bought a few years of peace between the communities. It's documented that Rolfe was very concerned about the morality of marrying a "heathen", but finally decided that it was OK because it was for the good of the community.
Not directly relevant, but here's an article on Powhatan marriage customs, as reported by English observers: https://encyclopediavirginia.org/entries/marriage-in-early-virginia...
So all the claims about Englishmen marrying descendants of Pocahontas are looking kind of iffy. The marriage of Thomas Pettus' daughter to Chief Wahanganoche is especially troubling. This marriage would have occurred around 1650 at the earliest. Pettus was a bigwig in the English community by this time and the racial separation policy had already taken effect. The general attitude of the English was that genocide sounded like a mighty good idea, and basically put it into effect in 1666, at which point the Patawomeck disappeared from the historical record. Even if Pettus himself was in sympathy with the Patawomeck, his fellow Englishmen would not have taken it lightly if his daughter left the English community to marry a pagan. All signs suggest that Christian Martin spent her life as a member of the English community, so presumably her unknown sister did too.
I don't know of any headrights on Christian, but we also don't know when Thomas Pettus and a lot of other prominent people arrived. There were a lot of Virginia courthouses going up in flames in both the Revolution and the Civil War, plus the usual ravages of time like mold, floods, and stuff getting so old and brittle that it just crumbles into dust. A lot of the colonial records must have been lost.
Class mobility among the English is hard to judge, but I'm sure there was more opportunity in Virginia than there was in England. A sexy, ambitious woman has always had a good chance of marrying above her station, and there are situations that can make a woman lose status too.