The service can work you must call #611 to reach the Care team to special order it for the migo.
Ask for a Locator Feature Code to be placed upon your LG VX10000 (on that device you can access the locator service by launching the mobile browser, selecting MY VERIZON > My SERVICES > FAMILY LOCATOR).
Then ask for a "Family Locator Child for MIGO" feature code to be placed on your Migo Device, which they can learn about on their "Codes/Pricing: Family Locator Line Usage Charges" Care Assistance page. You are correct this device needs no Family Locator Member application downloaded upon it.
Once the Care representative has done this. Place this phone on a window sill and turn it on.
Then go to familylocator.vzw.com, login with your LG VX10000 My Verizon login (there is an option to register for one if you do not have one yet), and then, click the RED activate button in the top left corner of the screen which sits aside your phone number for the MIGO phone.
Click the 4 checkboxes and hit the "Activate" button.
Once you have completed that step you can begin locating the phone.