Now, how to by mysterious/180 for the pick-up, hmm..
It really isn't that hard. Your part is to look good enough that it takes her breath away. Add a sexy smile on top of a big serving of old fashion charm, and she'll be wilting. Of course, she doesn't intend for you to know how you affect her, but that's okay, just keep being confident.
The mystery part is simply not telling her everything you do. Give vague answers. Don't lie. If you have no place to go and have to ride around...then tell her you went riding around......or went to the mall looking. The point is to have that secret, confident, suggestive smile that will cause her to wonder.
Pick the kids up and have a fun attitude. Don't hang around. Get them and get out as quickly as you can. That's important. That tells her that you really are getting a life and don't have time to stick around to see what kind of mood she's in or engage in conversation, KWIM? As you ride away into the sunset, having a great time with her kids, it should hit her a little bit that she's not a part of that. However, don't put all your eggs into that basket. She will have to experience this several times.
BTW, don't be surprised if she TM's you while you and kids are out together. Couples use their kids as a contact excuse.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!