I had a bit of a problem once there since on hard it's insanely stupid, and my work around was to turn off the auto target system and aim at paula at all time, result? flawlessly got to both doors with Paula at a 100% health, i'm curious to see you guys try that in a Speedrun, it seems far more efficient than the current strat
For speed we don't actually need to keep Paula at 100% HP (I'm pretty sure her walking speed doesn't actually change related to HP.) The current strategy of running to the end and just start blasting is the fastest just due to the lack of Oviraptor spawns. For every spawn it makes Paula stand still in fear.
With good shot placement and a bit of luck you can just get two Oviraptors to spawn during Paula 1, and in Paula 2 once you get to the end and kill the two Oviraptors no more will spawn 99% of the time (sometimes you can get super unlucky and a third one will but that doesn't tend to happen too often in my experience.) I don't have a lot of experience with Hard mode but I don't think Paula takes extra damage so it isn't necessary to play it safe.
If you are having issues with successfully doing Paula there is a couple of options that can make it a lot safer with only a small loss of time. The first being the use of the ATR to one shot the Oviraptors, you mainly lose time just from the menuing and buying the ATR. The other option is during about the middle of each section you can turn around and blast the Ovis with the shotgun.
As long as you only take two hits during Paula 1 you should be free to just run to the end of Paula 2 and start blasting. It might get a little close with her Health, but its actually very consistent and if she dies its usually from poor lines or missing the trigger for the ladder.