@surfsupjoe,
i just want to say that i have been going through the SAME thing. literally - we could be the same person with the same emotions and experiences. and i just wanted to impart that her guilt over not wanting to make a decision right now may actually encourage her to make the wrong one...ie run away. this very well could have nothing to do with you or your relationship or compatability...and nothing to do with her wanting to be friends. this is not to give you false hope - but it is impossible to know what she is thinking...for you AND for her. there is just too much muddling of the issues due to the grief and fear.
that said, i do know that YOU can make a very distinct choice here. you can walk away completely - hurt and heart broken and angry. or you can stand in there and do the one thing she wants most, but expects least - stay. tell her you agree with her decision, that you know she isn't ready, and BELIEVE it. relieve all pressure and expectation. be the best friend and best man you can be (get back to what YOU love as an individual....get your own life back starting right now!). have fun with her. lessen her grief by being the person in her life who cares so much to listen to her, respond to her. don't be a doormat. do your own thing, have your own life - but stand in there and let her observe it while still feeling your care for her. by doing this, three things happen. one, you lighten the mood again. you give her a place to laugh. and that IS love in action. two, she will begin to see how her mourning has actually prevented her from being with an amazingly caring person. this may not happen today or tomorrow, but it will happen. at some point the fog will lift and she will see what she has done...and in that her desire to heal should be augmented. again - this is you being loving in a very non-judgmental, non-pressuring kind of way. three - you reclaim your own life and individuality. in the event things work out, this will help the relationship. in the event things don't, you have already uncoupled and can move ahead.
and i know this all sounds mad. trust me, i so know. it will often feel futile and confusing and the absolute worst idea for yourself...but when you are in love someone who is sick...emotionally ill...a tremendous amount of selflessness is required. and i do not mean being a doormat. you have every right to set expectations and boundaries - and tell her those as they arise. she needs to start hearing that loved ones have expectations of her.
end of the day, based on what i've seen, i doubt she even knows what she wants right now - widows who ask for space AND say that love you - generally mean this is moving too fast, i'm not ready. you can hang in there and be the person she could re-fall in love with. you don't have to be, you can choose to find someone who can love you completely now. but you CAN wait for the day when she has the capacity to do that. and if you do (wait to see), live the best life you can in the interim. make a list of everything you want in your life and start going after them one thing at a time. in that, you yourself will be growing and healing at the same time she is. who knows the possibilities from that perspective.