I thought the midwife one was an absolutely beautiful image of women/womanhood but I didn’t see it depicting ‘gender’. Childbirth is a genuine sex-based physical, biological process, not a social construct.
To me - an image depicting ‘gender’ will be showing social/cultural expectations deriving from sex-based stereotypes, like the river one. So, say, a photo of young boys playing ‘jumpers for goalposts’ football in European football shirts/shorts/some topless, with a group of young girls walking past in full burka clutching schoolbooks (an image I saw once which stayed with me, can’t remember where it was though). Or, somehow depicting that men may be fêted for a high number of sexual partners whereas women may be shamed; or how men may be damaged by pressure to conform to macho stereotypes (not a photographer - not sure how you’d show that). Or even just a highly sex-segregated social scene that perhaps isn’t seen as particularly controversial or damaging - maybe men and women at prayer in separate areas of a mosque/temple etc, groups of men smoking & having coffee in street cafés whilst the women gather at home with the children, etc.
Lots of photos of people just being themselves, whilst lovely, isn’t really depicting gender IMO. Especially all the images of feminine-presenting males (the Hijra, the performer, the two(!) of transwomen, and to a certain extent the ‘non-binary person in field’) don’t show me gender - they show me people being free to be themselves, which is wonderful, but pretty much the opposite of gender.