If your goal is to have Jas live on your farm and experience a rich narrative involving her, Shane, and Marnie, these are the recommended mods:
The mod offers a unique proposal option that feels more intimate and personal, reflecting the player's journey and relationship with Jas. This makes the marriage feel more earned and special. stardew valley jas marriage mod better
Troubleshooting with other mods
Historically, direct marriage mods for young characters have been controversial and frequently removed from major hosting sites like the Chucklefish Forums If your goal is to have Jas live