So I recently got the secret empire TPB and was reading it and had a multi-part question:

Part 1: does america chavez only make portals to other universes(2) or can her portals take her to places in the main 616 (3)

Part 2: if she can only create portal to other universes, is it to the same spot she originally opened the portal or can she chooses the location. Either way, why didn't she just make a portal to another earth and then once there make a portal back to earth 616 inside the sheild

Part 3: if she can travel between location in her home universe, why didn't she make a portal back to earth seeing as after the sheild went up there was no reason to stay up in space

Is there some information I missed that states the sheild prevents her from making portals back to earth or something, either way I'm sure she could have just made a portal to another earth, bring everyone along, heal them up and then return to get through the sheild similar to how they did in the actual comic