No idea what you're talking about. Is it Greer's comment? “Elizabeth’s unbroken silence is the truest measure of Jan Morris’s enduring masculinity”
What's sexist about that? Greer (and we) understand women's experience of coercive relationships with controlling men. We all understand why Elizabeth was silent and we don't criticise her for it. We understand coercive relationships and how a person who seems charming in public can be a tyrant behind closed doors. Elizabeth has had 'the luxury of silence' as you put it. No one knows what she thought.
Or is it this? Her groundbreaking memoir on the transition, Conundrum, which revealed nothing about her sexual life, sharply divided opinions. What's sexist about that? I think when you're writing about your transition and SRS surgery it's natural for people to wonder about your sex life. It's also fairly widely known that Morris had sexual relationships with a number of people outwith marriage. In what way is it sexist towards Elizabeth to mention this?