I started as soon as my dogs were puppies. When I would put them in there I would say "go to your bed" or "kennel" ( i have 2 that respond to) and then say good boy/girl etc. I only had to do it for a few weeks and they picked it up. All I say now is "bed" or "kennel" than they go running to thier kennels.
I think offering a "treat" after saying "kennel" and putting her in there she will learn. Follow with "good girl" etc. Make it exciting and happy. She will learn.. they all do.
