Is it a way my girlfriend from the Philippines live in the US without marriage right away, she has visit here already

Again, as long as you are a USC and you intend to marry her within 90 days of her arrival, you can seek a K1 visa for her. 

Your girlfriend would need a nonimmigrant visa that allows her to remain in the country for a longer period of time. She could look into applying for a student visa or work visa. This would allow her to remain in the country for a longer period of time without you having to rush to marry. You can read more about nonimmigrant visas at http://myattorneyusa.com/nonimmigrant-visas.