as for the spaying, I was never really for it in the first place but my Mrs wanted to avoid puppies....didn't work out that way.
Re: spaying, having had an unspayed bitch have repeated mammary tumours, some of them cancerous, cost me a ££££££ortune twice to have the cancerous ones removed (not to mention the worry), she then got a secondary tumour in her elbow and I chose to not amputate at her age so medicated for pain until it wasn't keeping her comfortable...

I would never ever keep a bitch unspayed again. (Oh and she also had pyometra, so another op for that, and it did make her proper poorly, took her a while to get over that one.)
Check with the vet, there is an age by which you need to get them spayed to reduce the likelihood of mammary tumours.