David - Thanks for mentioning Sophie. Very few biography's mention her.
Dennis and Sophie also must have mourned the loss of their family. I think Thomas loss and taking in two additional mouths to feed must have been overwhelming. I think he did the only thing he could do to fix the situation, Leave the kids for a short while and find them a suitable step mother, He chose wisely.
So when is this "Old Enough To Know Better" supposed to kick in?