Yeah, she's pregnant. Perhaps not too far along, but it's hard to tell from that angle. What color fish is she? As that might explain the pink gravid spot.
I have a female guppy that looks like yours. She is always HUGE! She did have fry a while back and just before she did, I was able to see the black eyes of the babies in the pink gravid spot. It was kind of cool as you could REALLY see the little things (where as with the black gravid spot fish it is harder to see them).
So, even though your fish didn't make it, I hope this information will be helpful if you (or someone else) has a fish like her.