Great breakdown! Just one thing:

I ask to see her phone to check if her story adds up.

For newbie RPers: This is not okay with a plate. Totally reasonable for a LTR.

Do you mean it's okay to check your LTR's phone whenever you want, or just in critical cases like this? Because if you establish that you can read her phone, how would you respond to her probable request to be allowed to read yours as well? There's many situations like this, where I want some kind of "right" in the relationship, but I don't see how I could justify denying her the same right (and not look unreasonable), although I wouldn't want to grant her the same right.