A correction here:
Humans have (normally) 26 chromosome pairs. The reproductive DNA (what goes in an egg or seed cell) consists of 26 single chromosomes. The actual chromosomes that get picked are chosen at random. Upon fertilization, these chromosomes meet up to form 26 pairs once more. So from 26 pairs there are 26^4=456976 potential combinations.
This means that certain blocks of DNA will always inherit together (assuming no mutations).
Now, this means that Kaguya (26 "otsutsuki" pairs) gave birth to two half-humans (26 otsutsuki chromosomes and 26 humans chromosomes). Upon procreation, the result for Ashura and Indra can be almost anything, from 26 human chromosome pairs to 26 of Hagoromo's otsutsuki chromosomes and 26 from their mother and anything in between.
The same applies to Naruto and Sasuke, except it's even less clear. We don't know what chromosomes Naruto has that encode his Uzumaki DNA, nor do we know what chromosomes Hinata has that encode her Hyuga DNA. Their child could inherit both Hyuga and Uzumaki chromosomes, or just Hyuga and Naruto's non-uzumaki (or vice versa) or neither.
Since Himawari has yet to display typical Uzumaki genes and Boruto typical Hyuga genes (that is, a proper Byakugan), it's already quite clear that they won't pass on their parent's combined power. The same is true for Sarada: She isn't showing a Rinnegan.
Then, their children would have to inherit the particular "clan chromosomes" once more, without loss.