She's my best friend, so is he. they dated for two years. Is it cool that I tell her I like her?

They broke up 3 weeks ago, He's my best friend, and so is she. The thing is now that she is talking about meeting new guys and stuff it makes me jealous. I could barely stand around as they were an item, now I can't stand to see her even mention guys. on a scale of 1 to 10 if I were to rate how much I genuinely like this girl. its a 10. Do I tell her how I feel?