My GSd had her second litter 9 weeks ago, she was a brill mum and her nine pups have now all gone to their new homes. I would now like to build her up a bit, as she is a bit slimmer than normal. I have kept her on the puppy food I fed her on throughout pregnancy, and am also giving her a tin of tuna a day. Or should I just let nature take its course and let her gradually put the weight back on over the next few weeks. What would you do ?