When you lack confidence in the area of approaching women, your mind will find ways to get you to avoid doing it.
Don’t listen to it.
This is a girl that you have been thinking about approaching while waiting for the bus for months.
You should still approach her, even if your mind is trying to make you believe that you have waited too long.
Unless you actually approach her, you can’t really determine how she will respond.
Trying to make that determination prematurely because you believe that you have waited too long is never advantageous.
A way to approach her properly is to greet her, introduce yourself and say something in reference to the bus.
Something humorous tends to work very well.
When you can open up a conversation with a girl by making her laugh, you have taken the first few crucial steps in getting her relaxed and thereby more receptive to you.
Yes, it is correct to approach her.
If you don’t, you will never know how she would have responded to you.
You can ask her out at the end of your first conversation with her or you could build rapport with her first through texts and phone calls before asking her out.
If you spend a good week consistently communicating with her, you should have built up enough rapport by the end of it.
It all comes down to what you feel more comfortable doing.
But either method can result in an affirmative response.