We use in fact to add more detailed information to what has just been said: A: Did she pass her driving test? B: Yes, she did; in fact, she’s now taking an advanced driving test. In fact is commonly used in front position in a clause, although in informal situations, it may occur in end position:

You can place a comma before, after, or around “in fact.” Before “in fact,” we include it as a sentence finisher or part of a larger clause. After “in fact,” we use it as a sentence starter. Around “in fact,” we use the phrase as a parenthetical element.