I am going to block her phone number.
Do you have any reasons to block her number?
Because she has to be taught a lesson
You shouldn't cut someone out of your life who cares about you. You're putting them into a really awkward situation if you block them from your phone, especially if you know them in real life. Just keep their phone number unblocked and speak with them less if you don't want to spend time with them for now.
Why don't you want them to learn their lesson?
I'd rather think a better idea would be to just communicate with her. Do you think you can think about how she would feel when someone they know suddenly removes them? She might care about you a lot, and it's worth mending your relationship over.