You have to wait until its a) accepted by the gov and b) she has gotten her refund or has paid the tax she was supposed to. After that you can file an amendment.
Not necessarily. I setup a payment plan because I knew I did not owe the money. That way instead of being out a huge chunk while I waited for the amended return to be accepted I ended up only making three of the twelve payments and getting the money back.
You don't have to wait until it is processed, you only have to submit the 1040X after the original. It could be a few days, week or up to three years after the original is filed.