Girl advice?

so theres this girl who i really like but she has a boyfriend but now they're on the verge of breaking up any time now. should i let her know how i feel now or wait a little bit? i dont know what to say too or anything that'll make it obvious.Girl advice?
Just be around! Attention will make her feel better, but not too much! She will be too busy by getting her life back on track.Girl advice?
start flirting with her more but don't tell her how you feel until way later on when you are in a relationship with her if it gets to that point, if you tell her how you feel about her before the two of you are together, she is going to classify you into the desperate nice guy category and you will then be stuck in the friend zone forever. Do what jerks do without being an asshole like a jerk, be confident, be a leader in the relationship, be unpredictable, treat her like you've known her for a long time and she's like a best friend, that way you won't be nervous around her. Hope I helped you and good luck.
Wait until she is single, and when she is upset about the break up, be there to comfort her.
wait till she is completley single