We are not aware of any law that would prohibit you from giving the debt collector her public contact information. (Though depending on the type of debt it may be outside the statute of limitations at this point. The statute of limitations for most consumer debts expires in 4-6 years in most states.)
Once the collector has your ex-wife's contact information, the calls to you must stop. If they don't, the debt collector is probably breaking the law and you can report them to the FTC and your state attorney general, or even consult a consumer law attorney.
For more information on what to do if you are being called about a debt that doesn't belong to you, please read our article: Debt Collection For the Wrong Person