Here is the full list of all 22 The Timeless Child - there are Prologue achievements.
Solve Paintings Puzzle without ever making a mistake
Try to access the basement playing as Chris Hunt
Solve School Puzzle without ever making a mistake
Solve Books Puzzle without ever making a mistake
Find and read all sheets
Complete the prologue playing as Emily Wells
Help solving Greenhouse Puzzle without ever making a mistake
Listen to all George Wells tapes
Ring the Time Bell for the first time
Complete the prologue playing as Chris Hunt
Open the map for the first time
Play with a friend for the first time