Info to ask for?

Sis in FL is wanting to know what types of financial information on her ex she should provide and she can legally ask for?  Can anything be asked for asked for that relates to his wife?  Sis has already asked for W2s, tax returns, employment offer letters, etc. to try to prove his income.  Also how much can he legally bring into the mix of finances the&nbsp... associated with his wife and her filing for bankruptcy and the foreclosure on his wife's house (only in her name)?

His wife is not party to this, nor required to support the kids so her income does not count. Sounds like she has asked for everything she can, whether or not he complies is a different story.

Even if wife was liable (which she is not), how would her bankruptcy, etc, help Sis?

the basic items one must comply with are in Rule 12.285 FL Fam. Law Rules of Procedure.  Anything beyond that you have to do a request to produce. 

What are her options for his refusal to produce (e.g. employer, W-2's, joint tax returns, etc.)  He wants to go to mediation so that she will learn how far he will go to make sure she does not get this information.  He has already started to cut back on child support and alimony in order to make sure that she understands that she will not get this information.