Well normally I allow them all to eat as much as they want, :0) As far a Rory I would not starve her , may cut her daily food by a cricket, or worm here and there. You may be right , a companion even if it's another female, may put some spark in her life, lol
I don't think it is healthy for them to get TOOOOOOOOOO hefty, if it is limiting her movements/activity than it is not a good thing. That is your judgement, observe her and see if she is basically inactive, or having a harder time jumping around or climbing, than she used to.
If not, and she is still bouncing around, and all is well than let her be. She is just a big pretty girl 
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PHEve / Eve