Zomg she's such a beauty
I think the mounting will stop/subsided once she's spayed. Might even help her to calm down a bit
. How engergetic is she? she might be the type of dog that you will have to throw a ball around before a walk just to exert some of that energy. Walking beside Molly is a really good sign, it might mean she will learn a little quicker with her . I also think your playing it real smart, walking them together and a sleep over is a great idea.
From personal experience, For a second dog I thought it would be best to get a boy instead of having two girls. However,Hubby fell head over heels for our Shih tzu Sparkie and that was that. I'm glad it worked out that way actually, I find Maggie kind of mothers the puppy a little, and Sparks seems to learn things faster if Maggie is doing it.
Anyways, it all sounds good to me...then again that picture may have impacted my opinion
but only a little
Noel- 4 year old black and white cat
Felix- 6 year old black cat
Maggie-3 year old Newfoundland Dog
Sparkie- Puppy Shih zu