Would 然后他们怎么了 work?
I am Chinese. The one you provided would work too!
This is more like
"So what did they do after that?"
a small difference in meaning i would say
她们后来怎么了 should be accepted too, I guess.
They later what happened. Hover translation was a fat lot of use on that.
I believe I learned 你们昨天有什么事情了？as what happened to you yesterday. would the chinese say 他们后来有什么事情了?
I was doing this as a review exercise a month after finishing the course, and I got it exactly right. So, as Homer Simpson sighed, "Everyone's stupid but me..."