Upvote:1
Since she wants to travel on her current passport before picking up the new one I'll answer this question in 2 steps.
I have renewed my US passport in multiple countries. Every time the embassy took my current passport with the renewal application and advised me that if I need to travel within the next X amount of weeks (duration to get a new passport) I should apply for a temporary/emergency travel document and they will provide it to me. So, in this case, it is pretty clear that I couldn't travel on my current passport. Once they gave me the new passport they would drill holes into the old one.
My wife applied for her passport renewal (not a US one) in her home country. She did not have to submit her passport with her application. She was free to travel using it as long as she did not pick up her new passport. Once she went to pick up her new passport they voided the old one (I don't remember if it was holes or some stamps on the whole passport and cut off the machine readable portion).
Now coming to the Philippines Embassy in Muscat:
Under the Please βexpediteβ my passport FAQ
However, while the new passport is being made in Manila, you will continue to hold your present passport, which means you can still use it for employment purposes or for travel, if it is still valid.
Considering the validity extension, she can travel on her current passport as long as the expiry date hasn't passed and it hasn't been voided by the authorities.