Kicking your friendship up a notch is a commitment and with any commitment comes pressure. Being through what she did, now is NOT a good time to put more pressure on her. And why can't you support her more unless she makes you her BF?
Work it this way instead. Just let her know that you will be there for what she needs, even if it is her privacy. Call or text message once or twice a week to check in from time to time. Get her through this dark hours FIRST, then
may be she'll be ready to spend more time with you to work towards being more than "friends"