I was thinking of breeding my chi with a jack russle I've never bred dogs before should I do...?

I'm afraid I agree with everyone else and say don't do this to your dog. Aside from the fact that it will be fraught with problems - more for your dog than you - it would mean there will be even more dogs ending up in the pound and being PTS. You don't have any experience of breeding, you don't know the background health of either of the dogs, what if there is something wrong with them genetically? I say, save yourself and your dog a lot of pain and heartache, get her speyed and let her enjoy her life as it is.