If you want her to leave her alone, you should've just said "Oh so that means you're single?". She'll never talk to you again.
Are you insane? When someone pulls out a weapon on you, you don't "try to take it". That's how you get your hand impaled or sliced open, or worse. You're not fucking Rambo. When someone pulls a knife on you, you run. You want to know why?
Because shit happens. And it doesn't matter if the chick is a 5' nothing with no muscle structure to speak of. If that bitch takes one step forward while you're trying to "handle" her, that knife is going into your gut. This isn't fucking anime. You're not going to be able to stop it. You lack the skill set to survive those scenarios.
Good. I hope you try this someday. I can't wait until some bitch buries a knife in your hip because you decided to sweep her legs and she fell on you. Forward momentum is a thing. Again, this isn't anime. You're not fucking Rock Lee.
I understand the sentiment, but trust me you do not want to get stabbed. Escape in any scenario regardless of whether you're a shrimp with no muscles or a champion MMA fighter should always be your first option.