Bracknell is on 10 May. Wokingham is probably not an option in 2015 as the 2014 event was cancelled and they transferred people's entries to 2015. I don't know if there will be any mechanism for those unable to make the new date to transfer their place to new people.
I live in Fleet and it's a great event - same day as Reading and a lot cheaper.
There is also the Surrey half marathon from Woking to Guildford, but that may be a bit too far for you to travel.
I'm happy to do races that aren't UKA registered but I have noticed that there are more UKA events now - probably because the fees were reduced when all the clubs started affiliating their events to ARC rather than UKA due to the ridiculous costs. And I guess there some pressure from runners who do like to see their results on Pof10. What I don't like is when someone says that their event is "run under UKA rules" or the course is UKA measured, but then you find out that it's not a UKA registered event that year although it might have been a few years ago. I think it's bit naughty if you run a PB and wait in vain for it to appear on Pof10.
You could also see if the Mortimer or Julian Farrell 3k races allow children as young as 6. Next Saturday afternoon he could do the 1k at Alice Holt, and there is also a kids' race at Swallowfield on 22 September (I think). But nothing as far as 5k. Some 5k races have race limits of 11 and 13, but only parkrun is really going to work for you at the 5k distance. There are junior parkruns at Woodley and Saville Garden and "full" parkruns at Reading and Woodley to name but two in your area.
I've just returned from a holiday on Jersey and am still hoping for a parkrun by my next visit in May 2015. There are so many runners there - I'm sure there would be plenty of demand from locals and visitors. Maybe this year's marathon might create some interest? The Guernsey one has just taken place, it would also be good to see a parkrun on Guernsey. Surely the islands have an ideal venue?
I checked with my husband and he said that the "lightbulb" moment was basically what Martenkay says above - steer in the direction you want to go. He said that learners tend to keep the handlebars rigid whereas you need to move them. I don't know if that helps, but maybe it will