Lucy is an energetic and happy girl. She doesn't seem to have any interest in her school studies, and hates homework and studying in general. However, she shares her mother's passion for dancing.
Appearance-wise, Lucy is the perfect combination of her parents. She has short, navy-blue hair with a bandana worn over it, just like her father. From her mother, she got her tan skin along with eye shape and color.
Lucy will first appear two weeks after you trigger Luke and Selena's marriage ceremony and sequence of rival events that occur before they both decide to get married. You'll get a letter in your mail from Selena and Luke. They've had a baby girl, and ask you to come and visit them to meet her.
Visit Luke and Selena at the Blacksmith's. A scene will play where you will be introduced to the new born baby, Lucy. As a newborn baby, you cannot interact with her. Even if you have a rattle, you cannot play with her nor can you pick her up, talk to her, or give her gifts. Lucy will remain in this stage for two more weeks before she grows up.
(NOTE! She will NOT exist in game if you have both Selena and Luke unmarried or have married either of the two.)
Two weeks after Lucy is born and you've visited Luke and Selena to meet her, you'll get another letter. This time, Luke and Selena will tell you that they're going to take Lucy for pictures at Simon's to celebrate her growth. They want you to meet them there, so you can introduce yourself to Lucy.
Go to Simon's Photography Studio any time after getting the second letter, at a time when the store is open. Here, you will see Luke and Selena, as well as Lucy. Lucy will introduce herself, and from this point on you can socialize with her. You will be able to interact with her like any other villager, and befriend her. Lucy does not get any older in game.
Exploration of the Mine
When you pass through the mine road going towards the blacksmith, you may trigger the event where you see Lucy and your child asking each other if they are strong. As expected, both agree and jump in glee. Lucy will ask him/her if he could be the leader, your child responds with a "yes." Both will leave for the mines and start their adventure.
This event can be triggered with Heath and Roy as well, and will play out the same. Each child you trigger this must be at 2 hearts or more.