Omg, I'm so sorry
.
Thrombosis (well, and embolus too...which is a thrmobosis that starts traveling, and can be critical very quickly) is something familar in humans (think of "DVT" or deep vein thrombosis in humans - this is why they tell you to "move your legs" on airplanes often).
Depending on where emboli lodge themselves (ie, where they end up after traveling) and what underlying health problems are also present (diagnosed/undiagnosed) really determines whether the outcome is hopeful or, unfortunately, deadly (even instant).
Did this baby have any health problems that your friend was aware of?