20 down: Kiss and make up? Fair dinkum? (6)
Fair dinkum = really is clear as day, but the rest?
19 down: Fan of a juvenile explorer on radio
Adorer = fan is all that’s certain here.
21 across: Leading female experiment curtailed mid-step… (padre) (9)
Here, leading female = matriarch, which implies that mid-step = arch, but how does experiment curtailed = matri?
22 across: (matriarch)…for father to step about? (5)
The answer here is padre, which kinda means that to step = pad, about = re and to step about = padre = for father, but how does to step = pad?