in short, you can never be 100% sure in quantum mechanics. refer to the uncertaintny principle.
Nature itself doesnt know for sure.
Looking at an electron changes its behavior. Refer to the double slit experiment.
In quantum mechanics, an electron or any particle can be in multiple places at the same time and can even to some extent move backwards in time to change its current state. Also multiple places at the same time doesnt mean the same info is stored on it. Thus yes they could be observable in both states, however, following the quantum uncertainty principle. we can never be sure.
Its fun stuff. Not too hard, just needs worded simple.
And about entanglement... well once two particles are entangled and share their quantum state, both show opposite behaviors. Eg, one rotates clockwise, the other will rotate counterclockwise. That said. If the entangled particles form a system, then yes you have one example of both states at once. Until you look at it.. xD