Alright I have this issue with my spouse, I was already married to Ysolda before I downloaded this mod. I then built the house in falkreath and incase you are asking I did have beds for me and my spouse and when I went to Ysolda to make her move there, she didn't have the option to do so. However, I did find a solution and it was to uninstall the mod and when I went back to Ysolda, the option appeared.