I dropped working on this mod a while ago, because the in game features have been improved a lot since I started it. It might still work since it does not override any game code. Feel free to use the comment thread to post if it still works for you so that other users are informed. Or if you are a modder I give you permission to create and publish a derivative of this mod as long as you link back to my profile.
Tested for patch 1.91
Since the “Discuss Expanding the Family” interaction is just designed around pregnancy and does not work for gay couples or single Sims, I added a new interaction which lets your Sim suggest to another Sim that they might adopt a child.
UPDATE EA actually changed the “Discuss Expanding the Family” interaction to work on singles and homosexual couples who might now consider adoption. The disadvantages of this interaction are that it only works on Sims that live in a house and that it might also result in the adoption of a cat or dog (if you own the pack). If you do not care about these limitations you can now use the original interaction if you want to get someone to adopt. If you prefer to have more control you can use my mod.
Mod Functionality
This mod adds a new interaction “Suggest Adopting a Child” that can be found with the friendly interactions.
If the interaction is successful a random toddler or child will be added to the target household 
The toddler or child will be added to the family tree and the target Sim and their significant other (if there is one) will be set as parents.
Every Sim can suggest an adoption but only YA or Adult Sims can be the targets of the interaction. Your Sim has to be friends with the target Sim.
The suggestion will not always be successful and the Sims will get moodlets depending on the result. Sims with the trait “Family Oriented” will be affected more, both positively and negatively, but they will also be more successful.
If the target household is already full the suggestion will always fail.
And the interaction is not visible for members of the current household, since it is not meant as a cheat 
Packs required
No packs required.
Changelog
05.09.2022
NEW Added Polish translation
22.04.2022
NEW Added French translation
17.03.2022
FIX Interaction not working without debug cheats enabled
Translations
Available languages:
All other languages will use the English texts (so far). Since I added a bunch of strings I’m not really comfortable with using automatic translations, but if anyone would like to provide translations for their languages I’d be happy to add it (and give credit of course).
Installation
Unzip and drag both the package file and the script file into your Sims 4 Mods directory (not more than one folder deep).
Compatibility
This mod adds a completely new interaction and does not override any game resources, so it’s quite unlikely to conflict with other mods.
Credits
Made with Sims 4 Studio
Thanks a lot to andrew for the tutorial on Python modding.
Thanks a lot to scumbumbo (RIP) and the other people in this thread for letting me know how to add interactions.
Terms of use
My mods are published under the Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) license.
If you share my mod please link back to this upload. (Published on: 2022-03-12 12:00:00)
