Not for me but for my mum. I have eyes for GSD only so can't think past something wolf looking and huge 
Requirements are:
Small to medium ideally but not set in stone.
Easy to train, intelligent.
Good with small children as I have a baby who my mum babysits twice a week along with my dogs.
Must be able to be let off lead and be easily housetrained (so i think this rules out lots of toy breeds?)
Must be able to be left alone for short periods without loosing the plot.
We are not a gun dog type family and she does not really like spaniels, retrievers or Labradors. Also no bull breeds.
The ideal breed would come out with me and my GSD daily as we live in the same street, so not easily squishable but sensible enough to be happy at home once we have been out and about.
She loves corgis but they are very hard to get hold of. If only I could shrink a GSD in the wash it would be ideal but we think 3 very large dogs may be a bit much. This one would primerally live with my mum as I said but it will have dog company lots of the time.
We have thought about whippets but I have friends with them and they are mental and not easily trained 
Poodles are also a maybe but my MILs are snappy nightmares?
So...can anyone think of a GSD like dog but smaller 