My ex wife discharged the mortgage in ch 7 I filed and reaffirmed she now thinks I need to refinance to get her off mortgage so she can buy a house

There should be no need for you to refinance.  Secured debt that is not reaffirmed, such as a mortgage, should reflect on your wife's credit report as 'included in bankruptcy' and show a $0 balance, and not drop off her credit for approximately 7-10 years.  She should dispute the reporting online with the credit bureaeus if this is not how it is being reported.  Some companies will delete the reporting all together but that is not required.   Anyone running her credit for the pupose of obtaining a mortgage should understand the non reaffirmed debt reporting and understand that she is not responsible for the debt.  She will likely have to provide a copy of the discharge order and possibly a copy of the petition and Statement of Intent which states her surrender of her interest in the property/mortgage.