Track stolen laptop serial number

If you're sure that you know who's got it, why would you need to track it? To be sure that it's in her house? You could just call the police, I suppose, though this doesn't sound pretty.

Your ex-wife? You could try asking her to return it.

Call the police and let them handle it , It's not something that we can help you out with here.

ask your son's mom to return the laptop. or call the cops, state your problem, show them the proof of ownership if it belongs you/your son.