Aw this must be so difficult for you and for your bereaved girl... I guess its tricky to decide when the time is right to do the introductions, maybe give her (and yourself) at least a few days or a couple of weeks to grieve and adjust so she's got time to come to terms with her loss and is ready to sccept new friends. Do your piggies live in the same room as each other already and get to smell each other and talk to each other? If not this is often a good first step, put the cages close together so they can get to know each other through the bars. The next step would be introducing on neutral territory like in a playpen or in the bathtub and leaving them a good few hours together to sort out their new relationships. If that seems successful then they all move in together in a newly cleaned cage that you've changed around a bit and added some new furniture so it doesnt seem like the new piggy is invading the others territory. Its great you are already thinking about the welfare of your bereaved piggy, pop over to the "Behaviour, Bonding and Bereavement" area of the forum where you will find some excellent expert guides on how to help your bereaved piggy adjust to her loss, and how to best conduct the introductions to the other piggies x