Lady M, I fully appreciate where you're coming from on this.
me and my OH haven't seen eye to eye on this point in the recent past - I tend towards the same view as you, and certainly when Suki, Paddy and Flynn were kittens, they weren't allowed out before they attained 6 months of age and had been vaccinated and neutered. Back then, we didnt have a secure garden anyway, and lived backing on to a metro line and a busy street network.
Of late, with Mac and Ross and Dickie, OH wanted Mac and Ross to go out while it was summer and decent weather, albeit only when we were out with him. I didn't. Even though we live elsewhere with a wide open space to the rear of us, I still felt it was too risky.
OH got his wish, but both kittens found means of escaping the garden, in spite of our best efforts. It gave me numerous uneasy moments. I didnt know a minute's peace.
We lost Mac to a road accident a day before his first birthday - he got a taste for wandering early on, and wanted to follow another cat he'd made friends with who was a bit older than him. No-one's fault, but heartbreaking just the same.
Dickie was allowed out from the age of 9 or ten weeks by his owners. I didn't agree with that either, especially as him and Ross became firm friends, but whereas we would only let Ross out with us and - come the winter - he was in by dusk, Dickie wasn't. As a result, he would find hikmself locked out, and would sit outside our house and cry to be in. His own people never heard him. It was always us who would get up in the wee small hours, having heard him pawing at our locked cat flap and wailing pitifully in the frost and the snow to be in.
As a consequence as the months went by,Dickie has virtually moved in with us, and we firmly class him as "one of ours." He's extremely welcome, and we love him as much as we love Ross, but even his owners acknowledge they shouldnt have let him out and left him to his own devices when he was so yuong. They key here is "being left to his own devices" which is not what you're proposing to do with Tippy at all, but I mention it just bby way of illustration.
There are so many associated risks with letting any cat out, and it's hard to envisage them all, but what I would say - long story short - is however "cat-proof" you believe your garden to be, unless it is "properly" cat proofed with correctly designed fencing and netting, they will always find a way to get out into that exciting, inviting and unsafe world outside.
If you're willing to be very vigilant, and to stop up all the gaps you can think of, and then some more that you think may be way too small (but which won't be) then try it first with her on a harness when you can both keep a very close watch on her. And then enjoy the fun in watching her explore her garden and get used to all of the exciting things that will be going on there for her.
