you shouldn't be so harsh with Sakura,she is ready to sacrifice her most important thing (after her love for Syaoran of course) in order to try to save her friends,even if the outcome already seems irreversible
the future that she has foreseen must be so desperate that even her luck would be useless,so that it is better to trade it against another power.
or maybe that she has seen everyone dying except her thanks to her incredible luck,and that she refused to accept this fate because loneliness would be more painful than any other sorrow
...
moreover,until then Sakura wasn't so lucky despite what Yuuko said,remenber that to begin she has lost her memory and that she was obliged to travel through many dangerous worlds and confront countless ennemies in order to search for her feathers,and more recently she has had to endure a bitter event,the departure and the betrayal of clone syaoran,the one she has always loved and trusted.
and to finish she has been badly hurt when she has gone to the wild area so as to retrieve the egg required by yuuko
.
so Sakura's luck is protecting her from death,but not from suffering,grief,and physical injuries...in some way,we can say that Sakura CAN'T DIE even if she wanted to,so her gift is maybe rather a curse,don't you think
?
