This is normal report. She is on chemotherapy, this traces pericardial effision is acceptable. It will resolve

Pericardial effusion can be reactionary or accidental finding. It is a subjective finding and sometimes pericardial fat also is confused with pericardial effusion. Trace amount of pericardial effusion is not considered significant and needs regular monitoring. If any particular reasons of collection of pericardial fluid like infections, post cancer metastasis, protein deficiency, renal dysfunction if any needs to be ruled out. She is already hypothyroid and that itself could lead to fluid collection in the Pericardium.