Good luck with this Flashy, if you can't get one at Argos there are several buy it nows on ebay which work out at about £15 if you add in the postage
cat carrier | eBay
I'm slightly envious though I do prefer adult cats to kittens. For 35 years we always had at least one cat, usually two, sometimes three. Our last one died in October and we have not got another as we want to go travelling for long periods in a couple of years when my partner retires, and it would be difficult to leave a cat behind or find a carer. Though we have seen folks on campsites with their cats on a lead, even cage birds as well!
I have heard that white cats can have some genetic peculiarities like some can be deaf and some have eyes of different colours. Be interesting to see if yours has! It'll also be interesting to see how she takes to the lead.
Whatever, I hope she gives you lots of pleasure - enjoy!