Hmmm.... kind of new to the brisket stuff, but I think the veterans will tell you that you will risk toughening it up if you try to hurry it along. First barbecue lesson for your wife should be: "It is done when it is done." No disrespect to her, but try to let her know that as much as BBQ is also becoming a science.. it is still an art... and art should not be rushed.
Now I know the above comment helps absolute zero, but I myself am building the courage to one day say this to my GF.
One of the guys here in his signature has a quote form his wife. It is as follows:
"Is any of that meat going to be done for TONIGHT's dinner!?!"
So know you are not alone in your situation.
Now I will hush up.. and hope a veteran can steer ya where ya need to go!