Clause 61.3 requires the Contractor to notify of a compensation event within 7 weeks of becoming aware of the event, would an early warning notice comply also?
No, early warnings and compensation events are separate processes and separate notifications are required.
The early warning and compensation event processes are distinctly different. The time bar that you refer to is only on the notification of a compensation event. If you have notified previously an early warning about this matter which at that time was a warning that it MIGHT be an issue, the time bar will still apply if you fail to notify as a compensation event when that matter switched from being a MIGHT issue to a certainty.
The switch point from when it went from might to certain is when the seven weeks starts from (i assume the fact you mention 7 weeks you are talking about the ECS - the Subcontract version rather than ECC).
Early warnings you should notify as soon as you become aware, and failure to do so may result in the event being assessed lower as a result in accordance with clauses 61.5 and 63.5 if and when that event is assessed through the compensation event processes.