Here are a little examples of what you can do in MMV with your lovely fbx wife.
You have to convert your model into VRM then export it as .vrm or assetbundle but your work will be rewarded when you see your wife in MMV.
Here I just enjoy watching my girl dancing, changing clothes and a little interaction after dancing but you can do a lot, A LOT more in MMV!

MMV by Snail921
https://snail.booth.pm/items/4435894
https://discord.gg/26KCnDVtB9