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 character was on a task as was travelling with a group of people. 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.