First of all, have you tried the cat deterrants, i.e. Perspex type sheet on earth filled flower pots with bricks on top (which hogs who aren’t keen on going in boxes seem to think is still outside) (and your cat would still be able to watch them) or other feeding stations.
I Love Hedgehogs changed their recipe after the dangers of mealworms became known. They now use calci-worms, which have a higher level of calcium than mealworms. Nut and sunflower seeds are not good for the hogs, fed on their own, but as part of a balanced mix they are o.k. Some of the information about I love hedgehogs hasn’t been updated (online, some feed bags, etc.). I use it myself and have had several conversations with the makers about it and I believe that they are reputable manufacturers who have looked into producing a food with the correct balance of nutrients, etc. and monitor it to make sure it fits in with latest knowledge, etc. I should say that, other than checking up on them from time to time and being a customer, I don’t have any other connection with the makers.
Whilst most cats aren’t interested in that type of hog food, there are exceptions to most rules! So I would still put something in place which puts cats off – as suggested above.
What we feed the hogs is supplementary to what they can find in the wild, although in long hot dry spells, it can be harder for them to find wild food. It is very important to link as many gardens as possible, so that the hogs have access to more habitat. That also has the benefit of making it less likely that the hogs need to cross roads, with all the hazards they present. Some hogs can travel up to 2 miles in a night. So you will realise that they need access to lots of gardens!
I’m sure you leave out water, anyway, but lots of water sources in the garden for the hogs are very important in this hot dry weather. I always leave water available for the hogs all day every day. Wide, shallow plant saucers are ideal for this.
Good luck. I hope you manage to reach some compromise between the cats and the hogs.
P.S. I wouldn’t move the hogilo. Sometimes they won’t use hog houses, etc. which we provide until they become ‘part of the furniture’. Find somewhere suitable and leave it there, would be my advice. But there may be other reasons why she didn’t visit. I wouldn’t have thought just moving it would put her off visiting. Don’t forget the hogs eat bugs, so if it is providing a food source, maybe that is good too!
P.p.s. gestation period about 4.5 weeks but can be a bit variable. But it’s very difficult to assess when they actually become pregnant. The courtship ‘circling’ doesn’t always lead to mating and even if you see a hedgehog mounting another, you can’t make assumptions. Peak time for hoglets being born is June and July.