White caps are normal, but if you start noticing that there is a lot of white (the caps seem bigger than usual or if she is having some poops that are just whites) that could be from the excess calcium. While some people give calcium supplements for weeks and weeks with no issue, she might not need it if she hasn't started laying again and giving extra calcium for a long period of time can be hard on the kidneys which have to filter it out of the blood. You can also throw off the calcium to phosphorus ration with supplements. On the other hand if she is still eating the tablets straight (or not eating enough feed) it's possible she is feeling calcium deficient.... Chicken nutrition is quite complex which is why I try to let the formulated chicken pellets do all the work. What is she eating these days? Any change in her condition?