seems it might be too much for her to be involved with?....you being sick and possibly your personal life situation? Was she in support of you and hubby separating or staying together?
It sounds like it's more than just not wanting to be your friend and that it's the combination of stuff that's involved.
not all friends have the ability to be friends when the going gets tougher.
Worse is that she's your neighbour....meaning she'll always be the reminder.
It's very rude, however, for her to not return your calls or at least to have a proper severance of the relationship.
Anything seem it could be possible?...or am I totally in left-field.
Oh, is she going through something herself where you may have been perceived as being not a good friend to her?
I know it hurts.
Keep us posted if there's any change.
q