Mighty, Funny how she showed up at the same store you did and was right behind you. Who is stalking who? I don't think this was an accidental move on her part. If I recall Walmart has a lot of parking spaces and why did she choose to park directly behind you unless the parking lot was full? I may be wrong, but it sounds like she did this deliberately to set the ball in motion to get in your face. Funny how the cops were called after you said something.
No matter what you say or do, she's going to lie to keep him close. She's the one that really looks stupid, as you did not stalk her nor did you threaten her. She's just plain nuts. I wouldn't trust her as far as I could see her.
As for your stupid xh...he deserves her. He's going to defend her no matter what happens and let's face it...he knows you wouldn't do stuff like that. She's got him by those jewels and twisting them so hard he doesn't know what hit him. It's going to take a lot for him to see the light of day or he'll be singing at a high pitch for the rest of his life.
BTW, I think you were actually nice in what you said to her. She's lucky you didn't raise your voice for the entire parking lot to hear what you said. Now, you know what you are dealing w/and you'll have to refrain from saying anything to her. It's okay to look her in the eyes, but don't say another word. I may be wrong, but she's going to try to goad you again into saying or doing something. She knows exactly what she's doing and the wedge that she's driving between you and your xh will only get deeper and wider to keep the two of you at odds over co-parenting and getting along for the sake of the family.
I hope you can get a lot of your kitchen work done today. Put that anger to good use in hanging the drywall.
I think you are doing great and btw, I'm proud of you! Don't let them see you sweat!
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.