Is her breathing still laboured? If so ask for them to check if she has fluid on her lungs and whether she needs a diuretic. When mentioning heart problems say that you have heard that a repetitive upper or lower respiratory infection can indiciate heart problems. Though it is possible that this is an infection that is resistant to the antibiotics she is on, either way though if she has fluid on her lungs she will need a diuretic. Are her lips, nose or feet blue at all? that is another sign, as is being difficult to wake from sleep, weight loss, ascites (fluidy type pockets down the sides), hooting, nodding in time with their breathing, random coughing.