***** NOT A TEACHER *****
Hello, Fatoumac:
I believe that a comma would be used by some American writers in a sentence such as this:
After Mother asked, "Are you two awake?," we both pretended to still be sleeping.
Here is an example that I copied from the New Yorker, a very sophisticated magazine known for its attention to "good" English:
In a recent article titled "What Do Banks do?," which appeared in [another magazine, he defended the banks' executives]. (NOTE: I foolishly did not copy the whole sentence, so the words inside the brackets are only my idea -- in order to give you the idea.)
As you can see, "After Mother asked 'Are you two awake?' " is an introductory adverbial clause. So you need a comma (pause in speaking).
"Which appeared in another magazine" is a non-defining clause that needs commas in front and at the end.