Tell Her You Love Her

I see it as being addressed to either the singer's past self concerning a first love or to an ex's new love or a friend. For the past self interpretation, she is telling herself not to be afraid of love and not to make the same mistakes of being too afraid of getting serious or being closed off. If you take the ex lover's new flame view, she's telling them to cherish her because she still loves the girl and wants the best for her. The friend interpretation is perhaps just giving advice to someone who has never been in love before