Watery Brown Discharge

I'm a PNP and have very little experince in women's or even adult health outside of nursing school, which was awhile ago. I'll do paps, OBCP, and STD testing on teens, but for the most part, if it is odd, I'll consult the Pediatrician or send them to OB.

During one of my sick visits this week, the mother of the patient started feeling me up for advice on one of her medical problems. I immediately recommended her to call her doctor.

But I'm curious to know what it might be:

42 YO female who says she has spotted off and on for about 2 months, then this month started to have intermittend brown watery discharge from her vaginal area. Lasted about 2-3 days and then went away.

Any ideas? I'm just curious at this point. I thought of the possibility of a miscarriage, but the mom (without me asking) made it very clear there was no possible way she could be pregnant (not sexually active).

I'm sorry about the lack of information- but I wasn't seeing this person, and didn't want to ask questions because I was not going to give her any advice other than to call her provider.