This is a simple mod that lets the player initiate a pregnancy or adoption event with a spouse by selecting "Have a baby" when going to sleep.
It can be used with the latest version of Free Love to select which spouse to initiate the event with.
NPC spouses must have at least 10 hearts (by default), the farmhouse must be upgraded to have a children's room, and an adoption or birth event cannot be already in progress.
I haven't tested whether it actually works with player spouses; please let me know if it does or does not.
Technical
Requires SMAPI, uses Harmony.
Compatible with Mod Updater for automatic updates.
Implements a Generic Mod Config Menu interface to change config settings in-game.
Code is at https://github.com/aedenthorn/StardewValleyMods.
If you want to complain or ask for help or help me test my mods, you can visit my Discord server.
A list of all my mods for Stardew Valley is available at https://www.nexusmods.com/stardewvalley/articles/895.