Limiting the channel list

My 91 year old mother has trouble seeing, and is struggling to use her X1 remote because she can't see the buttons.  She also gets lost in the long channel list and can't find what she wants  to watch.  I tried going into the guide and setting up a "Favorites" list.  But even when the guide is set to display only favorites, when she presses the channel up/down buttons she is still cycling through all the channels.  If I use the parental lock feature and "lock out" all of the channels she doesn't watch, will that prevent them from appearing when she uses the channel up/down buttons.  (Or will still still land on the channel with a screen saying the channel is locked?)  (She lives an hour away from me, and I can't test this at my house, because I don't have Comcast.)