You can also wait until the end of

You can also wait until the end of the chapter for her to come to you. She'll come to your house and admit that she has fallen in love with you. She says that she knows you only think of her as a little sister, but she wanted to tell you how she felt. You then have the options to either reject or propose to her.

If the later is the case, she accepts the feather and fantasizes it being a dream come true, then tells you that she'll be waiting for you at the Villa. After Romana and Sebastian bid Lumina farewell, the both of you go around town telling everybody the good news; then after, you go to your farm, exactly like with the other three bachelorettes.