Hmmm... This is a tricky one. I'm not estranged, but have a few friends who are and have heard arguments both ways about this issue. IMO, if an AC cuts off their parents, they shouldn't expect to inherit, shouldn't even want to, really, if they seriously want NC (no contact). In fact, I get what some posters are suggesting, that some AC might really not want it. Also, I totally get the "don't want me/don't get my money either" attitude that some EPs express. Like some posters, too, I wonder how many EAC even give that any thought or if some of them just expect the inheritance will be there?
Regardless, if, for some reason, I became estranged from DD, I would still leave her some money/possessions in the end. Possibly, I would leave some (more?) directly to my GC, but I would leave DD some, as well. Otherwise, it would feel too much like "vengeance" to me and extending the "war"... "beyond the grave." But that's just me.
Purple, I'm astounded that your mum said that to you even as you were reconciling or trying to. IMO, it's just another sign that she really has nothing to give you, dear, both literally and figuratively, nor, apparently, to any of your sibs. I'm so sorry. Hugs!