I'm a 52 yr.old woman having brownish discharge a week after my period, is this normal for my age?

It might be.  Don't you just hate answers like that?  Well, it depends (there I go again) on your periods.  Is this the first period in a while?  First brownish one?  Or have you been having normal regular periods all along?  What meds are you taking?  We want both prescription and over-the-counter, including any & all dietary supplements.  Any pain?  Any foul odor?  Fever, sweats or chills?  Any change to your bowel and/or bladder habits?  

But in the end, it's your doc who needs those answers.  So my opinion is that you should go see your doc.  Good luck!