She didn't call her personally a cis woman, she called natal women in general cis women. You lot do yourselves no favours with this langauge policing. Ciswoman is a perfectly normal and acceptable turn of phrase, and is particularly helpful to differentiate when we are talking specifically about things to which (cis)women and trans women react differently to. You don't get to dictate other people's normal use of language.
Some people find the term birth mum and adoptive mum offensive (she's not my birth mum, she's just the woman who have birth to me, she's not my adoptive mum, she's my mum). You absolutely ought not use them to talk about someone who ahs said they don't like this terminology. But it's still fine and normal language to use in general.
Btw I do not identify as a cis woman either, I don't like the terminology because I think it implies that I confirm to all the social aspects of my natal sex, including those that I find oppressive. But that I have these associations to the term does not mean that others can't use it.