Find all original seven snow globes in the game. They do not need to be sold to Jane you just need to get them in your inventory.
Goodspings - At the Goodsprings cemetery by one of the head stones (wooden crosses) about two graves west of where you were dug up.
Hoover Dam - In the Hoover Dam visitor center on the desk in front of you as soon as you walk through the door.
Mormon Fort - On the top of the bookshelf in Julie Farkas' room.
Mt. Charleston - In the Jacobstontown lodge on the disk in front of you as soon as you walk through the door.
Nellis AFB - In the Nellis Boomer Museum, located to the right as soon as you walk through the door on the table.
Test Site - At the Lucky 38's cocktail lounge level behind one of the cash registers.
The Strip - In Vault 21, on Sarah's nightstand. Ask for a tour and she will point out which one is her room.
If you have any other problems this video should help.