From the picture that looks a female. Males have red markings on the nose whereas females tend to not have any or its very pale, also the dorsal find red is brighter on the males. If you can look at her "stomach" you can usually see tiny balls above the anal fins, these are the eggs. I cannot tell from the picture, but her general shape is suggesting more that she is carrying eggs. If she is acting weird at night time this is because tiger barbs usually spawn at night. - the changes of you seeing the eggs the following morning are very slim because they will eat the eggs rapidly.
If you cannot see any eggs inside her then try the cooked de-shelled pea. Tiger barbs are very greedy fish and do suffer with constipation, bloat and plain obese issues. - Tip when feeding only feed a tiny amount and spread it right across the surface of the water.
Hope this helps