Hard to say. But I can offer my experience. This has happenend to me when an albino female or male is unhealthy. I have purchased some that have been very pale and it takes sometimes afew weeks to get their health back- so lots of food , very clean home, a lot of wood- where as in some store sthey will not have any for them and it has resulted in pale , weak looking abinos. You mentioned she looked more bloated this morning, has there been a change in their diet recently is what I am wondering? Sometimes a change in diet as indifferent algae wafers, not properly washed prepared veggies can cause digestive issues, or internal parasites can cause discoloration in my experience.
You also said that he was picking on her and you were unsure if she might be stressed, or if it is normal mating behaviour. I am not sure what you mean by 'picking on her'- is he attacking her or something to that effect?
In my experience courting in yes a very passionate affair, but not usually leading to severe stress or unwellness. In fact it is quite funny to watch them and usually a very gentle sort of nudging or closeness from the male to the feamle and then vice versa. The actual spawning can be very passionate in that sometiems there is a lot of substrate disturbance and a lot of chase, but I have not had the occasion myself where a female or male apears to have been injured or become sick by it. Vice versa actually in the end is seems a relief to the female to rid herself of the eggs and then she will eat constantly but very pleasantly and usual behaviour, just not interested in the male anymore. A sunken abdomen where the eggs were and then will just eat anything and everything, sometimes after spawning an albino famale may be a little bit pale but ususally only for a day or two and there is a noticable sunken abdomen where the eggs were, but from the pictuire it looks as though your female has not laid yet. The male will be busy with his dady-duties if there is a spawn.
I would question diet or introduction of a new plant/decoration for a possible parasitic source. Also may be bloat, but you would need to provide more details as to her condition, diet anything new in the tank. I assume your parameters are all within good range.
I do not know if any of this helps but there are many brilliant minds here on this site and am sure someone will have other ideas if mine do not help- here's to hoping all goes well with her!!!
All the best,