Am doing this on phone as laptop died, so apologies for formatting issues. And for some reason, I struggle with summarizing my book :(.
Carla finds herself in the middle of a battle for tradition when the heir to Death is revealed to be a woman. If she doesn't protect the Heir, no one can die. #A #CF
Carla transports dead bodies by day and souls by night. And when Death is forced into retirement, a war breaks out when tradition is broken and the heir is revealed to be a woman. Now, if Carla doesn't protect the Heir, death will end and no one can die. #A #CF
These actually follow my CHARACTER + PLOT/CONFLICT + STAKES formula quite well! The only questions I have are what is this tradition? Do you have the space to specify "patriarchal tradition" if that's what it is? Whose heir? "Death's heir." There are a couple places you can be a little more specific, especially since it's not quite clear that Carla isn't the heir... For instance you can easily rewrite the first one to read for more specificity: "Carla is in a battle fighting patriarchal tradition when Death retires and the heir revealed is a woman. If she doesn't protect Death's Heir, no one can die. #A #CF"
The second one, since it is longer, can answer the question "WHY?" Why does it have to be Carla? What is special about her? That I can't surmise from what you've given me already, but maybe I can give you a framework to work from?
"Carla, a [insert occupation or what makes her special], must protect Death's female heir when he is forced into retirement and war breaks out as patriarchal tradition is broken. If Carla can't [do what?] to protect the Heir, no one will be able to die. #A #CF"
Honestly though... This is just me being nit-picky... Your two originals are perfectly workable pitches! Good job!!!!