
Sarah firstly I'm sorry to hear that people would not be friendly when you just ask for simple advice and I hope that doesn't turn out to be the case.
I don't know how long ago your girl was spayed, it could be as recent as last week or 6 months ago. If it was very recently then you must allow for all her hormones to settle. I don't think she will feel the pup has come from her as such unless she was going through or about to have a phantom pregnancy when she was spayed. Its hard to answer that one not knowing how long ago she was spayed, but I would perhaps take her in with you when the pup is due the 2nd jab to get her checked over. She could have some sort of infection that is causing her to drink more and because the pup is now in the house you are relating it to that.
Your pup should not have its 2nd jabs if it still has the runs. To have the runs this long is not ideal so I would go along on your appointment time and again discuss this with your vet. You don't want your little one getting dehydrated.
The fact that they both seem not themselves I wonder if they have picked up an infection or virus that is manifesting itself in slightly different ways due to thier ages. Whichever I think a trip to the vet for a check up would be the best plan.