Have you ever heard of the idiom "Shit, or get off the pot"?

People always miss chances because they don't reveal their true feelings to those they care about. I think telling her depends on the circumstances. Are either of you married, arranged to marry another, or are dating someone else? If she is single and your culture allows you to marry whom you choose, tell her your true feelings. If she likes someone else or is already taken, you better move on...