Maids & Masters v0.14

It's kinda story locked, but there are still things you can do with it.

If you find the headstone, it's similar to the two ruined Estates in the swamps in that you have the option to repair or destroy the headstone. The consequences for what you do (if anything) become relevant during the second Haunt, and some other things become available after completing the second Haunt. The state of it will also be relevant in Act 3.

It sounds like you've encountered a remnant of spaghetti code. You're not locked out of it by progressing through the story.

There's a switch that tells the game whether you've found the place and know what it is that needs to be flipped. Once it's flipped, you'll get a bit of dialogue every time you enter the map that'll tell you that you can work on it and roughly what to do. If you're not getting that dialogue and you've already been there, you might've just found the place before you had Phoebe around to tell you what it is. If that's the case, go inside the shack, check the chest (even if it's empty), then leave the grove and come back. That'll flip that switch and let you go about fixing the place up.
If you're getting dialogue that says to come back alone when you can't invite someone yet, that means I need to update the dialogue.

I do, but it's a Patreon benefit. I typically don't invite people outside of my Patrons to join it.

I don't mind being bothered, though. I typically only check most things once or twice per day, but I like talking about my work, even if it's just finding and fixing bugs.

Well, let's try to figure it out. For anyone who doesn't want to see spoilers or how the sausage is made (so to speak), look away.

To get it out of the way, sharing your save will give me a lot of insight into what's happening, if you don't mind doing so (just keep in mind I need both the numbered save and the global.rmmzsave, or I won't be able to load the save). If you don't want to share it publicly, feel free to find me on Twitter (or X or whatever it is now) and DM it to me there. Also, I apologize if I repeat anything I've told you before, I just want to be thorough.
For the mechanical bits, it is possible to get her pregnant before the game phase changes, but you might have to try a few times to get it to happen. Deirlinn has roughly a 28% chance of becoming pregnant every time you try. If you were successful, she'll have an extra line of dialogue every time you repeat the scene while the screen is black. When she gets pregnant, the game checks the current game phase and adds 18 to it. If you have Trophy 0 from Arrival and make Punchinella active, there's an instance of her between Phoebe's house and the elder's house. She'll tell you what the current game phase is, as well as confirm whether Deirlinn is pregnant and what game phase she'll give birth in.
Once the relevant game phase comes up or has passed, the birth event will trigger as soon as you enter the final version of your Estate's yard. That means if you see weeds and your garden and pool look like crap, it will never trigger. Same with if the Freeze is active. If your pool and garden are fixed up and there's no snow on the ground, the event can trigger. So if you did get Deirlinn pregnant in game phase 0, the earliest the event can trigger is game phase 18. If you left Cumhaill after the funeral and returned, the game phase may have been 1 or 2, meaning she'd give birth on (or after) game phase 19 or 20 respectively.  For this particular example, she can't give birth on game phase 19, because the Freeze doesn't end until game phase 20.
There are a few things that could be happening that's causing you to miss the event before the second Freeze. If memory serves, it's possible to go from game phase 18 into the Freeze without going outside, and if you do that, Deirlinn's stuck waiting for the Freeze to end. The second Freeze ends on game phase 20, so if you did end up not getting her pregnant until game phase 1 or 2, that would explain why it isn't triggering. If you want to confirm that, you could try continuing on and seeing if the birth event triggers after you've completed the Freeze.
As an extra bit of information, if you're worried about Kala's bonus Freeze objective (since that requires Deirlinn being in your nursery), you don't need to worry about that locking you out of getting the second Freeze trophy. The trophy doesn't require Quinn or Teely, so if you've completed one (or both) of their extra objectives along with everyone else's, you'll still get the trophy.

I hope this helps.

Every Hold that needs one has a Writ somewhere.

There might be two different Holds you're referring to, and both are locked behind progression. One opens up after Viridius (though you can open it early if you do a certain thing) and the other has a Writ that's given to you as part of the interlude between Act 1 and Act 2.

Thanks for the report! Good news: it's already been fixed in v0.12.

Bad news: You'll have to use the Homing Stone to get out of there.

18 game phases (or supply cycles, to use the in-game term) after they get pregnant. The earliest it's possible for Deirlinn to give birth is immediately before the second Freeze. There's also a few points where the game phase can jump forward earlier than you think it would at the start of the game, so it's possible it was 1 or 2, meaning she wouldn't give birth until after the second Freeze since the event that triggers the birth event only happens from the final non-Freeze version of your Estate yard.