His Younger Sister Thinks She's In Love, How Does He Advice Her?

My immediate younger sister and I are very close...like super close.....I'm about 6 years older than her but we're pals....we talk about almost everything...We have other siblings~ elder ones but we not as close to them as we are to ourselves...She's the last and only female child in the house. On friday, out of the blue she just dropped it on me that she is in love.....I was still raking my head thinking of how to advice her to take the whole love thing one step at a time.....I didn't know she was about to drop another bomb.... last night after saying our night prayers she came into my room grinning....I asked whatz up...she sat on the edge of my bed and said 'I said Yes'......I was like yes to what....she smiled again even laughing....'I said yes to the guy that has being asking me out'. I felt strange!!!.........I just smiled and said cool....big girl. But this morning I woke up and am afraid for her..... Could she really be in love How am I sure dis is nt anoda sharp guy putting things in her head....How could she be certain its love...she's just 19......what should I do guyz..I am sincerely concerned for my sister...how do I help her avoid a heartbreak. Please drop your comments below...