Well with 16BBs Cove shouldn't have even played the hand in my opinion, even on the button. 7,8 off with 16BBs is just a waste of your chips. Be aggressive with that stack or fold.
So one way they could have played it better is to just fold. Once they've seen the flop, I hate the check with 7,8. You've played with a weak hand when you have no chips, you hit and you don't bet? What are they hoping for, a flopped straight, trips, a house?
I don't see why they shove either on the river, you're only being called by better hands, there is literally no reason to shove on that river with that action. Like you're risking your entire stack of 150 to win 54 chips. You either get a fold and still gain the extra 19 chips on the river, or you get called and lose your stack. When Firth calls the all-in the only thing as Cove you're hoping for is he got some goofy two pair by the river, everything else he is calling with is beating trips. If she just called 19, she gets to see the bluff, still get the 19 extra chips, or like in this case she can keep her stack if Firth has hit a monster. Firth likely doesn't have a jack with the way they've played the hand, so their bet is only a bluff or a super strong hand, it's so hard for it to be a middling hand here. Firth would want to protect a jack hand because of the flush draw on the flop, so the fact he checks means it is so much harder for him to have a jack hand.