@Misanthropist About this part it's not mentioned in detail but Mom & Dad
Spoiler!
Are together in the end while Thie, Dad and Agavert members go on a new expedition mom stays back to clean up the palace so that her daughter can live happily. Also Thie remains a 4 year old for 11 years or something because of the time distortion happened at the beginning of story and also she lost her memories Agavert members, her spirit friends and Lucarion feared them but she lata remembers them.
I like to post spoilers for the stories I find interesting because I don't have much time to read novel due to busy schedule you will find me in most romantic historical manhwa comment sections