If she can qualify for a credit card that can absorb the amount it should be easy to do the transfer. There may be a one time transfer fee. I recently opened a Chase Freedom, it has a 3% transfer fee but 0% interest for 12 months on balance transfers. This fee is usually reasonable when you compare it to 12 months of interest. Some people have posted that if you show a balance transfer during the application process you are more likely to get a credit limit to cover the transfer. I have never done it personally, so I am not sure.
-If qualified she can save some interest.
-She can make a lower minimum payment until finances level out. Or she receives a windfall of money (end of year bonuses and the like).
-You could separate your and her financial obligations faster if the new card is in her name only.
-If she does not pay it off in time it may cost her more in the long run (Transfer fee + Interest).
-She may not qualify for a large enough limit to cover balance.
BTW, you can cancel the Chase card even before it has $0 balance. You will still owe the money but Chase will freeze the account so no new charges will appear. Being on good terms can take some of the trust issues out of the equation but in my mind nothing gives peace of mind like "the law" (or a Court Order). I know I have trust issues, but money makes people crazy sometimes.