Welcome to YT!!
So glad to have you both here - can't wait to see pictures of your girls.
I think your set up for the pups sounds good. You might want to read up on crate training as an option that can often speed up the training process.
Give your kitty time, she may come around - at least to tolerating the pups, but it could be mths. My male Siamese - so easy going, could have cared less; but the female, like yours was another story and she still once in awhile gets annoyed at them for just existing
Definitely avoid the yorkies eating the cat food - it can actually be dangerous for them to eat it.
I would recommend a different food other than Iams. This is a decent website to read - its someone's opinion - but it does break down ingredients in just about every food out there and gives you plus and minus on each food
Dog Food Analysis - Reviews of kibble