I read through the mentioned study that is quoted in the article as the source for that number with a translator, but I cannot find anything relating to the number. On the contrary, the mentioned rates of abuse seem to be way lower.

In general, 24% of respondents are aware of the use of physical force (beatings, blows) in families among their environment, including their own. Every fourteenth resident of Russia (7%) witnessed domestic assault in the parental family, and every twentieth (5%) practices or is the object of violence in their own. Given the sensitivity of the topic of violence for the interview format, we can assume that this share in both cases may be higher.

(Translated)

https://www-levada-ru.translate.goog/2019/09/13/domashnee-nasilie/?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=de&_x_tr_pto=wapp

At the end it talks about which acts are generally considered domestic violence by married people, but it does not even talk about the rate of abused married woman in particular.

Maybe someone who can read russian can find something here that I cannot? But as of now I see no source for the claim.

Edit: Just to be clear: I am not supporting Russia's War. I am merely pointing out that the source for the claim does not actually support the claim.