(Will do. d8: 6 + 3 STR = 9)

The Blood hawk shrieks as the blow strikes and it heavily injured, but attacks again anyway. (Attack roll nat 20+4=24. Damage 3+4+2=9, strangely non-lethal damage.)

Helga grunts in pain and lashes out once again with her sword.

(Atk: 19+5=24, dmg: 7+3=10)

The Fire hawk is cut in half from the strike, but instead of a shower of blood, you are instead coated in... Stuffing? Regardless, the door to the next room is open, and you can go through it or check the cabinet.
(By the way, do you consider dragon born and teiflings monstrous humanoids or do you only want human-esc creatures in diapers? I only care because I use a wide variety of humanoids normally, so I just want to ask.)

(Dragonborn & tieflings I'd have to say I find "monstrous". As a rule of thumb, think physically alluring or charming humanoids.)

Helga spits out stuffing and dusts herself off. She decides to check out the cabinet across the room.

(Is nonlethal damage recovered after combat? If not, she first uses Lay on Hands to recover 5 hp.)

(You recover Non-lethal damage like you do lethal damage, either after a short or long rest, so you can use lay on hands if you don't feel like waiting.)
Inside the cabinet, you find two bottles of milk, one that looks like chocolate and one that looks like normal milk.

(OK, I'll hold off on using Lay on Hands just yet, b/c I'm starting to like where this is going.)

Hmm... Helga picks up the bottle of regular milk, inspects it carefully, and takes a very small, careful sip, bracing for the effects.

It tastes just like regular milk, but for some reason Helga feels much better after drinking it. However, she also starts to feel the need to use the bathroom. (The bottle gives 2d4+2 health back, and also gives a -4 consumable penalty. Also make a continence check. To do that, roll a d100+5, and subtract you consumable modifier. For every continence check you make, you also gain a -1 time penalty. So right now your check is d100+5-4-1.)

Ahh, the milk is indeed refreshing. (3+3+2=8 hp recovered)

(Continence check = 71+5-4-1=71)

If that's a pass... Feeling the pressure starting to build in her bladder after guzzling the milk, Helga decides to take a few minutes to put on one of the pink, girlish diapers she took from the previous room.

(Any positive number is a pass. It's too early for you to really fail yet.)
Helga is able to put on the diaper easily enough, and is able to proceed into the next room.