Love an introvert

Validate their need for distance without taking it as rejection.
Let them be the one to give signals when they need any type of closeness.

Express gratitude and willingness to accommodate them.
For example, assure them that you have accepted her introverted nature and will not force her to become someone else.

Show awareness and loyalty.
For example, when planning a date night, choose a calm location without reminding them that introverts like them need only calm locations.