Hi and welcome to YT.
The behaviour Annabelle displayed towards Angel is perfectly normal, a new member has entered her 'pack' and she needs to let Angel know her place in the pack.
She was also protecting her pack (you) and her territory (your house).
I have had my yorkie pup for 5 weeks now and I have had my older cross breed bitch for 10 years.
My older cross breed isnt happy about it and will sometimes growl or snap at the pup if she gets too close but things are gradually getting better, it just takes time.
Try to socialise your pup with lots of other dogs and get her used to other dogs coming into her home if you want to get another dog.
When you do decide on your new dog introduce them away from the home and then take things slowly.. seperate them when they are alone and you could try crating them in seperate crates next to each other at night and when you arnt home so they can get to know each other safely. Good luck.
__________________  Rachael & Poppy |