I hear (and have heard earlier) 'Hia bintika wa hia thakiatun ya Rania'. Are the 'a' (in bintika) and the 'un' (in thakiatun) not written (I do see all other vowel signs)?
In Arabic, we generally don't write the vowels. We only write them when there is ambiguity, or for beginners with reading. Here, I guess Duo is trying not to put all the vowels to make it as natural as possible.
and just to add, it should be ابنتُكِ (ibnatuki)
Why is it هوَّ and هيَّ?
Should it not be without the shadda?
Indeed. It should be without Shadda....