According to the Web of Deception website, it seems that a former assistant to then-Sen. Joe Biden (D-DE), Tonya Baker Garvin, who went on to work for Biden's successor, now works for Dr. Jill Biden's charity, the Biden Breast Health Initiative--and used the same email address, telephone numbers and street address for Joe Biden's local Senate Office that she used in her official capacity as Secretary for the charity.
That can be confirmed by comparing page 19 of this 2006 tax reutrn, with contact information taken from Biden's Senate website, viewable here.
The evidence presented by Web of Deception seems to suggest that the Biden Breast Health Initiative may have been using the government office to offset unusually large administrative costs.
The proportion of donations any charity uses for administrative costs relative the amount of giving it conducts is often used as a means of determining the best versus the worst charities. The Biden Breast Health Initiative's 2009 tax filing lists $54,867 in administrative costs, or approximately 60% of the total budget, compared to $35,026 for giving, or about 40%.
That puts the distribution well over on the high, or worst, end of the spectrum in that regard--and the charity may have even more troubling problems.