I have been a jobbing jeweller for 20+ years’ it takes max. 15 minutes or so to size mostly any ring. email me at prizlaATbtinternetDOTcom and we’ll arrange to do it by royal mail special delivery (£4odd for you to send) and i’ll get it back to by return, so seeing as they guarantee 24hr service, 1 day to get to me, straight back to you in the next post so she’ll only be without it for 48 hours. Will have to cover your return post but if it needs to be made smaller and I can keep the bit of gold that comes out then no charge for the job.
I have done over the years, without exaggeration(sp?), hundreds, of rings by post like this and never had a problem if you or your intended is worried about it going missing at the hands of the royal mail.
plus the girl who collects our post these days is “as fit as” so you’ll be doing me a favour anyway 😉
Congratulations by the way!