Character glitch, stuck on "Locating Server" cannot join

After playing many hours in our family world, my wife suddenly cannot connect and gets stuck at "locating server".  This is not a networking issue and not related to MCPE-36190 .  Please note the troubleshooting I have done:

1.  She can connect to another world, or a new world.  But she is fully locked out the family world.

2.  I have figured out (likely) the   glitch is  tied to her character in one specific world.    I copied the world to another computer and she still cannot log in.  Everyone else can connect. 

3. Her character is the only character that cannot connect, and the family world is the only world she cannot connect to (including copies of this world,  whether creative or survival)

3.  When she attempts to connect, on her screen are the words "locating server".  This message displays indefinitely with no timeout (we have gone 8 minutes and finally just cancel).  On my screen (I'm the host), I see nothing-  no message that she has joined.   

4.  Her character is visible in the online world, but utterly frozen.  We can see her, but cannot do anything.  Commands do not work on her.  She shows up in /list only, but nothing else.  Even in survival mode, her character hovers, and is untouchable.  On her screen, all she sees is "locating server"  (see screenshot 2).

4.  While the message "locating server" appears on her PC, she shows up in /list. All other commands on her character fail ("No targets matched selector)

4.  Please tell me what I can do to reset her account so her character can connect to this world that we have spent so many hours in.

If requested,  I can drop a .ZIp file of the world if that will help.  It is 243MB in size.