It's really not the lead that is the issue OP, so don't worry about it. Out of your entire first post I can't believe anyone would think that it was. Often when someone is behaving as your friend was you can reach a 'final straw' moment that catches everyone by surprise.
There are only so many chances you can give someone before they wear you out and you say enough is enough. Why give her one more opportunity if you have had enough now?
As I said before, if you really miss her and think she will change after you speak to her then go for it and try to sort things out.
But the cynic in me still feels that she has been waiting for five weeks for you to get in touch first, knowing what your family has been going through, rather than apologise to you and support you, because she isn't really a friend at all and wants to have you do the running and perhaps also the apologising.
And I think if you go back to her and say that she needs to change she will just turn this around and blame you rather than admit you are right and your friendship will either carry on in the one-sided way it always has or end completely anyway.
It always surprises me that people think they have endless chances to treat someone badly. I no longer see or speak to my PILs because of years of nasty comments and manipulative behaviour. They can't believe I won't give them a second chance but in reality it has been years of chances, many, many chances.
I've tried speaking to them before but it's never done any good. We've had years of spoilt Christmases and ruined holidays because they have thrown tantrums over not seeing us enough or not liking the gifts we gave them etc. Years of "do it our way or we want nothing to do with you."
When they brought my children into it and made cruel comments about our two babies who died I said enough was enough and now they are shocked because I have stuck to my word and cut them off. I'm not prepared to give them yet another chance to be cruel and upset me and now I am the bad guy because they feel it 'happened without warning and I won't give them a chance' when really they had eighteen months of pushing me to breaking point and ignoring all opportunities to make things better between us because it wasn't the way they wanted to do it.
They disowned us and are now surprised that I have taken them at their word and stopped seeing them. DH still speaks to them on the phone, but I'm done with them now.
Sometimes enough is enough, no hundredth second chances offered.