Hi marco and welcome.
Great theory, the only problem is the gun was found in her Jeep, I believe under the seat. She could have been hiding something else though.
Also while I am not the best at knowing the times of all calls, that call you see her on at the apartment building is not to the babysitter I do not believe. The sitter was called earlier and the call lasted almost an hour.
I too though have thought she may have been hiding from LE.
She did, however, head out of the area on a highway towards home or work for some miles but then she turned around and went back to the apartment complex for some reason...
I hope this info helps.