I have a few questions about the behavior of our two dogs after
introducing a third (puppy)

We have a 9 yrd old chow/shep mix and a 1.5 yr old beagle. Both are
females and are also best buddies. Yesterday we brought home a new 12
wk old female basset puppy.

Both are dogs have been very good around the new puppy, but I was
curious about the way they are acting. Our beagle seems to be very
curious and almost mommy-like. I was just wondering if after some
time if she will return back to her normal self?

Our older dog has been off and on. Sometimes she wants to play with
the puppy and other times she trys to avoid it. She has also been
over salivating, almost foaming. She has done this before when we
have brought a family members dog over but I was just wondering why
she does this. And will she return back to normal?

I am thinking that they will return to normal after a few weeks of
getting used to each other, it has not even been 24 hours since we
brought the puppy home.

Any comments would be appreciate.
Mark