Why don't you just offer to bring black condoms so you'll be properly dressed to help her mourn the death of her marriage?
Seriously? Dude, they're separated. It'd be different if they had filed for divorce already, but you're talking about wanting to date someone before then? Let her decide what she needs to do, then let her mourn, then laugh as she finds someone else who jumped in just before you did and has a rebound relationship with them.
WTF? What is it with people not being willing to give other people the proper and necessary space to mourn and heal? Are you so desperate to have a relationship with her that you're willing to deny her this that you yourself KNOW is a necessary part of the divorce process?
You've already answered your own damn question, but you come here in a passive-aggressive manner hoping we'll tell you that your first and right instinct was the incorrect one?
Seriously this whole I'm falling in love with her again bit sounds creepy and possessive. She's emotionally vulnerable. So you can be the honest and proper person, give her space, and be honest with her about what you feel and what you feel she needs by TALKING to her, or you can wedge yourself into a divorce that isn't even filed yet hoping that you don't screw her up worse emotionally in the process.
Here's a tip. Take whatever it was you felt when your marriage died, then the divorce, then everything else, think about how long it took you to heal from that, and give her at least THAT long before trying to stick your cock in her.
"Well, then," the Cat went on, "you see a dog growls when it's angry, and wags its tail when it's pleased. Now I growl when I'm pleased, and wag my tail when I'm angry. Therefore I'm mad."