Could this also mean 'In her case, I will make an exception'?
No, the Ihrem is capitalised, so it has to be the formal Sie.
Oh, sorry, my mistake. I didn't mean the pronoun (slip of the keyboard) but the tense - it's present progressive in the original, but it can also be translated future, right?
Yes, it could also be translated as future.
The comma is wrong.
"In Ihrem Fall mache ich eine Ausnahme."
ich stimme überein! No comma.
Ich vergesse nie ein Gesicht, aber in Ihrem Fall, mache ich eine Ausnahme.
— Groucho Marx
In your situation, i will make a exception. ?..was marked wrong why.........?
Probably because it's "aN exception"
It may have been marked wrong because you added the verb 'will'. I believe the phrase would be: '...werde ich eine Ausnahme machen'.
I wrote: "In your case I'll make an exception." That was marked as correct.