
Originally Posted by
clippyclippy
Sounds like the relationship you care more about is with your niece.
I would politely decline the invitation for the weekend, and if necessary, simply say that finances are tight right now, and weekend trips can quickly add up. You might even mention that you anticipate the restaurant may be out of your price range. Honesty should be appreciated. If it's not, then there a likelihood that anything you do or say that might not be received well.
Then send a card with a gift to your niece. It isn't her fault that they are the way they are. She will appreciate what you do and remember your thoughtfulness.