"She's not looking for guidance, she just wants to vent"
Well, she needs BOTH to be honest and a good family therapist will be able to SPOT that and offer both
You can't just let someone VENT and offer them NO HELPFUL advice, tha'ts pointless
The forgiveness comes with her MOOD.. .she can't forgive you when she is miserable.. the FT will help (if its a good one guide her into a healthier state of mind and a better attitude twoards her marriage.
You have to wait for forgiveness, you cannot FORCE that on her.. that comes along at the END of hte process.. it is NOT the first thing that's dealt with
You are doing well... she needs a warm sensitive husband and time to accept him.. keep up the good work