After some discussion with DM about Mrs MacNally's Maureen, we discovered this on the official Shirley Hughes website. So Maureen is definitely their daughter. I rather like reshape's explanation too.
Alfie's mum must be a social worker, although DM says nurse which I suppose is pretty close.
The wings in the hungry caterpillar bug me too. I didn't notice the cocoon though.
In Bear Hunt, the oldest female is required to do quite a lot - carrying the younger ones, putting on their shoes - and she's awful snuggly with the dad and has VERY frumpy knickers so I just assumed she was the mother. I am quite disappointed to find out this is not the case.
Books which only rhyme on some pages bug me too. We have one called 'Dig dig digging' which DS loves. Some of the pages rhyme perfectly while others don't even attempt to rhyme. Why don't they just not use rhyme on any page?
Hairy Maclary from Donaldson's Dairy has ONE page which I can't get to rhyme. Although wikipedia suggests here that at that point, when they encounter Scarface Claw, the type of verse changes so maybe I just didn't get this subtle difference. I have put the book back to the library now though.