The Corvia Galactica Universe is intended for advanced/Mature readers as some of the books have content that is unsuitable for children.
The content includes horror (with and without gore), stalking, mystery, genocide, revenge, intense drama, all forms sexual activity, off-color language, kidnapping, sabotage, murder, torture, espionage, inter-species relationships between intelligent beings of other worlds as well as other scenes that I am almost certainly missing.
These are the things that are common in many extremely popular Science Fiction, Fantasy, & Romance novels , movies and series.
An example is where the well-known popular captain of a WELL KNOWN starship has relations with different women (including multiple partners at the same time) on different planets, spaceports, and even aboard his/her own ship. (This captain is a household name to nearly every person over 20 on Earth who has seen him in MANY movies with his starship)
Another example is where a species has evolved as intelligent feline or canine persons. Both of these species on Earth as well in the Corvia Galactica Universe are pack type animals as defined by human standards and tend to have an Alpha male responsible for procreation with all females in his pack/pride, without exception. This occurs in several books.
In all cases, the rules, laws and beliefs of the world and/or jurisdiction are the deciding factor on whether or how the interrelationships are presented; if they are legal and acceptable by the planetary society or jurisdictional society, then they are acceptable to write about. Where required, age comparisons are given to indicate differences in ages and the way time is kept. Away from Earth, time ALWAYS moves at a different pace and that is crucial to understanding the points of reference.
For example: On Corvus Prime, 1 Year is the a little over 6 Earth years. So an 8 year (Dern) old there is actually 48 Earth Years.
Those novels will be indicated with an Asterisk ( * ) before or after the title.
Using Motion Picture ratings descriptions that I looked up, I would say that some of the novels would be rated NC-17 : LSV