1) You need to break into that phone. Much of what you need to know is in it.
2) That credit card, clearly the monthly bills are either online or going to her job. If online is she using a computer at home? If so install spyware. Run a credit check on her. You have her SS number on your tax returns. That will tell you what she is listing as a home address, like the hospital. You might find other debt she is creating behind your back. Myself, I would figure a way to to get a list of all the charges going back as far as you 2 were married.
3) VAR in the car along with a GPS.
4) Any friends at her work who can report on what she is doing?
Sorry you are here and hate to advise this but your posts have too many red flags to ignore. You have caught her in at least one glaring lie and there are probably more. Blurting out CUTE BIG GUY is too much. Right in front of your child.
Stop wasting time and just do it.
All this advice just seems counterproductive. What is the point really of all of this? This is why I tend to stay out of the infidelity forums. If you have to get a VAR, take your spouses phone, check all your bills, use a GPS tracker, spy through friends... All this advice that regularly comes up that people put weeks of effort into, the marriage is already toast. It's OVER!
Yeah you may be legally married on paper, but that is no kind of marriage. Just walk away sir. What is the point in torturing yourself going through all of this?
I don't mean to single out your advice btw Broken. I'm just using it as an example of what I see given all the time over here.
Do people really think that once you go down this path of spygate on your spouse that the marriage is salvageable at all? You are just prolonging the inevitable IMO. Just get out as quickly and painlessly as possible. Doing all this crap! What happens when you find dirt? You blow up and act stupid? Increase the chances of a knock down drag out divorce battle 10 fold?
Just go file, hand her the papers yourself, and say its just not working but you want to be fair in the split and will work as hard as you can towards being a good co-parent for your daughter and you hope she will do the same.