Cheers Guys.
It seems she's not liking the rat at all but I'm gona put this down to the size difference.
I've tried the methods you all helpfully suggested and she's not interested lol.
Rat fuzzies are rare at the mo, so I'm gona up her odsage on mice for a while and wait til she's a lil bigger and then retry.
I will let you know how this goes.
Thanks again for all your help, this forum rules!