How to find Jenny
Jenny appears in small villages and open Plains biomes where she can walk, interact and follow the player easily. She avoids caves, the Nether and hostile biomes, and prefers areas with flat terrain and decent lighting near player-built structures.
Where to search
Focus on Plains and areas around vanilla villages during daytime. Look for the mod's tall pointed-roof spawn house, which does not match any vanilla village building.
She may take a few in-game days to appear on a fresh world. Playing in Creative or Peaceful for the first search cuts mob interference.
Spawn egg and commands
In Creative you can grab the Jenny spawn egg from the inventory and right-click the ground to place her.
On Java the command is /summon jenny:jenny. On Bedrock and MCPE use /summon jenny:jenny ~ ~ ~ to place her at your current position.
If she does not appear
Confirm the mod actually loaded (Mods list on the Java main menu, or the world's Behavior Packs list on Bedrock). Confirm the world was created after the mod was installed, or explore new chunks the mod has not touched yet.
On Bedrock, verify that Experimental Gameplay options like Holiday Creator Features are enabled for that world.