Yep, I have an idea - I'd say it's her arsenic or witching "hour". DS1 was exactly the same, he was all good and fine until around dinner time and then he'd start up EVERY single night. I know they say "hour", but he would go on for at least 2 or 3 hours. We would take turns wearing him in a baby carrier and take him for a walk, he loved being worn and would fall asleep for a while. We'd tag team and lay him across our arms for a while, we tried lots of different things really. Unfortunately it's one of those things that you have to ride out, they eventually grow out of it.

I hope you both get some relief soon .