I think you're making a mistake by waiting if you hope to convert her to rats. the longer you wait, the less your chances. in my experience if you don't have them converted young, you've got almost no chance. Not saying it's not possible, but in my collection which has seen more than 60 carpets at one time or another, none has ever made the conversion to rats after about 18 months of age.
of all those carpets, 7 never made the switch, 2 JCP, 4 IJ and 1 coastal. a few others stubbornly made the switch. Most took rats right away.