It takes time for the property to show up on Trulia.
However, just having it listed among thousands of other properties is not enough.
You probably noticed that some properties appear a lot, while others do not appear.
There is much of "know how" in building a great marketing campaign on line.
Your agent needs to make sure your property is front and center to prospective buyers.
That costs money. Normally, agents invest money into selling their listings.
Or, sellers do - if they want to, to cover their agents' expenses.
Other reasons for not showing on Trulia: the agent/broker may not be members of the real estate board, or they are members of a different board that has no "sharing" with sites like Trulia.
Hope this helps,
Beachfront Realty, Inc.