I have finally persuaded my wife to give Eldritch Horror a try but as i am still a novice myself i would appreciate some suggestions as to which AO and investigators to choose to make the game enjoyable for a newcomer. I have the base game ,forsaken lore and mountains of madness. Thanks in advance.

I'd suggest you to start with Azathoth, BUT remove the darn mystery asking you to close gates whose symbol matches the current omen. It's very difficult to get the right sync and can be frustrating as starting experience.

Don't play with any of the OW or Encounters coming with Forsaken Lore, they add too much variability and imprevedibility to the game and as a starter, you need to understand the structure of the game and what the best strategy to deal with it is.

As for investigators, I strongly recommend anyone in need of suggestions to read this article, the guy is really good and makes some incredibly sound observations on the game.

Do not use any preludes. I would let them choose their investigator and you should choose Charlie yourself to help her. Giving assets and extra turns comes handy.

Thanks for the input, I should mention that I have explained winning will be difficult but the journey should be fun.