I don't think it is that simple.. Yes she has the money and determination... Time....

I don't think that she could just hop on a plane or boat and bam be there... I think this was a piece of the puzzle for her that she needed to find them but may not be the only thing she needed to get to Des.. She will I have faith in Penny and Desmond being together at least for a moment... Desmond needs to make sure Penny knows that he loves her and if he could go back and do it all again he would.. I think we are expecting too much of Pennny to be there to save the day already!

__________________
Please don't give up, Des. Because all we really need to survive is one person who truly loves us. And you have her. I will wait for
you. Always. I love you, Pen

DESMOND: I love you, Penny. I've always loved you. I'm so sorry. I love you!
PENNY: I love you too.
DESMOND: I don't know where I am, but--
PENNY: I'll find you, Des--
DESMOND: --I promise--
PENNY: --no matter what--
DESMOND: --I'll come back to you--
PENNY: --I won't give up--
BOTH: I promise. I love you.