I may be sceptical that the recent analysis of the cremation remains at Stonehenge with their near 1:1 male:female ratio indicates that the ancients were modern in their attitude to sexual equality - http://www.sarsen.org/2016/02/gender-equality-at-stonehenge.html - it would be lovely if they had been as caring and sharing as we are but I find the idea unproven.
What we can probably more certainly deduce is that is likely that the society was as monogamous as ours. We are so used to living in one that we forget that monogamy is not the default societal pattern.
"According to anthropologists, only 1 in 6 societies enforces monogamy as a rule."
"...of the 1,231 cultures in the Ethnographic Atlas Codebook, 84.6 percent are classified as polygynous, 15.1 percent as monogamous, and 0.3 percent as polyandrous."
But what has that got to do with the ratio of bones?
We can be fairly sure that the people who were honoured with burial at Stonehenge were not a complete cross section of society - there simply aren't enough of them. We can think of them as being the 1% of the time.
Some Roman tombs, and others, have an imbalance of sex ratio in favour of men (Gender, Manumission, and the Roman Freedwoman By Matthew J. Perry) because they contain slaves. In Ancient Nubia it is found that tombs contain more females maybe because of polygamy (Studien Zum Antiken Sudan: Akten Der 7. By Steffen Wenig).
I think the latter model is more important here, as I don't believe that these are the burials of a slave class. If the elite of a society are being buried in gender equality it suggest that the elite is also composed of equal numbers of men and women. Put aside any hope we have that such ratio is a result of equal opportunities and attainment; there is no society yet that has achieved that. The most credible conclusion is that the elite consisted of monogamous couples, and that maybe monogamy isn't a construct brought to our shores by Romans and Christians.