I just found your thread! Jazzie does look like a little angel. She is a very lucky little girl to be with you.
I told you Max was jealous when we brought Teddy home. The best remedy for us was to do things that Max loves to do, and then include Teddy. We went for extra walks and the boys had chews together. Some things were fixed in days, others took a week, or a little more. The last hurdle was Max allowing Teddy to sleep in my bed. That took a couple of months.
Put Josie first for everything -- greet her first and often, put her food down first, groom her first, everything first. Give her extra affection. This will reassure her.
Then let the dogs work things out between themselves and step in only if it looks dangerous --- or if you see something you don't like, redirect attention. When my boys were going to go at it, I would say, "Do you want to do tricks?" They know that means they get a kibble for each trick performed.
Sending best wishes to your J-pack!