Hello BC, you have just started doing this but know that it's such a difficult topic to let people know how you actually feel, but please my utmost sympathy and deepest thoughts are with you in every step you need to take.
No one could ever predict if someone you love is going to have a sudden cardiac because they may seem to be doing all the right exercises as well as eating to maintain their body so they keep in good shape, but our bodily functions are hidden, just as suffering from any type of depression is, so, please slowly talk to us about what she loved to do, there must be so much you want to tell us, either now or later on, but we're here to listen to whatever you want to say, just take your time.
Take care.
Geoff.