Well, you have to change a lot of lines to make them "Mom," and leave other lines unchanged in the moments you're talking about, I suppose there aren't many of those moments.
For example, let's say you have to change 80 lines that would say “Mom”, and leave untouched 20 lines that he would call her “Emma” And another big minus is that you have to update the patch for each version of the game, regardless of whether there was any content with “Mom”.
And so, you haven't updated the patch since version 2 because you know it would be a pain in the ass to update it every time. And a lot of people play without the patch because it's outdated.
What I'm suggesting will make your work much easier, and the patch won't be so much tied to the game version.
You do an auto-replacement and you don't have to replace 80 lines. Just the 20 where he has to call her “Emma”.
You also replace the lines where it talks about foster/step stuff.
Well, it's not a big deal, those lines can also be changed if they sound really unnatural. And some of them you can turn a blind eye to, the point will be clear enough. it can be sacrificed, most people won't even notice a little thing like that. And those who notice it will just ignore it as it's not critical.
The patch will work on any version of the game, you only need to add lines of new content that will require changes.
I understand you're reading a lot of lines looking for what needs to be changed. I know how exhausting it is.
Trust me, what I'm suggesting will make things a lot easier. The patch is pretty easy, but if you have any difficulties, I'll help you.
But it's up to you.