Starfire goes Nova and it's over. I don't see Donna getting the lasso around Kory when she's canonically the better combatant of the two. Even if she gets caught, I seriously doubt Donna can out-will her with the whole "I will not be caged!" motif floating around her appearances just before the reboot.
Does that really hold up though?
Donna, for all of her implied power, hasn't really shown much that impressed me since her ressurection - fight with Superwoman notwithstanding.
Starfire hasn't had an "official upgrade," but she had quite the push coming into the 2000s and again recently. Kory physically took it to Theia, ripped through Cronus' enchantment, practically soloed the Giants who were attempting to kill Hyperion, was a major asset in OWAW, one-shotted Braniac's ship, easily dismantled Titans of Tomorrow Wonder Woman (who defeated and captured Diana), etc.
Her stats up against Donna seemed to have scaled as well, despite Donna's many upgrades and incarnations. Starfire had to jump in front of Donna against Theia because Donna wasn't durable enough and Kory has more damage soak. Donna also couldn't hold Kory back in the JLA arc before she left for REBELS and had to call in friggen Mon-El to help (who was also quite impressed with her strength).