From your other posts it is clear that you are new to DirecTV service. One thing you really need to know is that the whole D* setup is far more complicated than a simple cable setup. Just moving a receiver from one home to another only works when everything is set alike. From your other post about your new install it would appear the you have a SWM setup at your home (which is still unclear if you ever got it to work correctly). So, now you have to know what kind of a setup you mom has. Do you know if it is standard or SWM? Did you take your b-band filter along with your SD receiver? You should not need it if she has a standard setup. Then too there is the issue of setting the receiver to work on whatever setup she has.
Until you get a better understanding of how all this works, it might be best to just enjoy her setup while you are at her house and yours when you are home. In about three to four months all this will be much more familiar and then would be the time to do your experimenting.