This is correct? Now, I did learn this stuff from a biblical perspective, but I learned that the יי is replacing the ים. Here, it would be אני אוהבת אתכם, ילדותי היפות.
Okay, so the ים isn't being replaced by יי, rather any plural word with a possessive first person suffix has a יי suffix, right?
No, only the female first person. Male uses single י suffix.
And some argue that female should also use the single י, but that's another discussion.