Basic pools...

GoldenSkull

Guilly 2099 gets added to the 5* basic on feb 11 and 6* basic on feeb 25... is it worth waiting? Should I save my shards for then or is the chance too low to really matter?

RU11011

A chance is a chance. You might get her, even if there's a slim chance. If you really like Guilly 2099, I suggest waiting.