Been doing a bit a research on heart conditions for toddlers. Seems there is a wide range of thing that could be involved ... some can be fixed with relatively non-intrusive procedures (such as inserting a device through her tiny circulatory system to repair things if there is a small hole in here heart). Others, can be much more complicated and life-altering.
Won't know more until the ultrasound is done after the first of the new year.