There is, but, just make sure you know what you're doing. if i remember correctly, same sex marriages break your save. just remember to use checkpoint to back up your save!

where do i find it?

Yes there is, but you need a place to plug in an SD card. (assuming you do since you modded your device) You can find it on github. Just look up 'Tomodachi life save editor' Just be cautious and have backup saves since if you do too much at once it corrupts your save data

there is, you can find it by looking up tomodachi life save editor on google. i HIGHLY recommend backing up your save first though. it is VERY buggy and really easy to corrupt your save data.