Well you can try maybe ever other feeding to see if she really needs that second mouse but if they are truly jumbo mice she may not need that volume of prey yet. Do make sure the second mouse isn't cooling a bit whilst she's eating the first one. Sometimes a blast with a hot hair dryer really ups the temps on f/t mice and helps the snake zero in on it more.

Also don't believe in the rats are better than mice myth. BPs have been proven time after time to do as equally well on mice as rats. Sure you may have to feed multiple mice rather than one rat but it's really about volume of prey and good healthy top quality prey than anything else. That and a consistent weekly feeding schedule will always produce a healthy adult as far as I'm concerned (and I have both rat and mouse eating BPs in our collection).

Here's a perfect illustration of this. Here are 4 ball pythons. All are 06 hatched, all are about the same size and age, all eat each week.....2 of them always take mice, 2 of them always take rats...which is which????