The two procedures can be done at the same time.
In a cancer operation not only is the breast tissue removed but the skin is removed as well. In that situation, the reconstructive surgeon may elect to place a tissue expander to stretch the skin over time and return at a later date to place the permanent breast implant.
Since this is not a cancer operation no skin will need to be taken, allowing the surgeon to place the permanent implant at the time of the mastectomy. In fact, the nipple and areola can also be maintained, which will help the final cosmetic result.
This is not uncommon and your general and plastic surgeon will be able to help you and your Mom understand the options available to her. She should do well with this procedure.
I wish you all the best.
