Hi BLT
That’s great news you have hoglets there!
Young hoglets start venturing out with Mother hog when they are 3 to 4 weeks old. In about the next 10 days they gradually begin to go off on their own. At that stage they only weigh about 250g. (information from Hedgehogs by Pat Morris). So, at that stage they still look quite small and it sounds as if those you mention are already going it alone.
Hogs aren’t territorial, as such, but they have ranges, which can overlap. It’s possible either the hoglets have dispersed from their birth area into your area (i.e. are possibly not her hoglets), and/or Mum is concentrating on another part of her range to avoid being pestered by the youngsters. There are also other reasons why Mother hog may have gone missing, so it isn’t necessarily a sad outcome for her.
Having said all that, if you are ever concerned about hogs behaving strangely, out in the open during the day, etc. or very small hoglets on their own, you can ring your local carer/rehabilitator – you will be able to discuss things more fully with them and take their advice. You can get the number of your nearest ones by ringing BHPS on 01584 890801.