Looking for the title of a book I read about 5 years ago though I believe the book was a lot older.

Essentially the main male character was on a task and was travelling with a group of people. The mode of transport if i recall was a boat and they were on a remote planet traveling via a river. One of the group was a father to a young female infant. There's a reference to alien artefact that essentially reverse aged a female scientist (the baby) a day at a time and the father is trying to undo it. Also a line I remember is the father used to say see you later alligator and the daughter will reply that awhile crocodile until a day where she forgot.

I believe the book may be part of a series. The author though I don't recall the name, has written other works that have received awards. The book or series may have received one too. Which is probably why I decided to read it in the first place.

Question never asked anywhere else.
I am from Australia, book was a papercopy bought locally.