PIO for Singaporean Citizen on Green card

[rakeshkh]

I and my daughter are US citizens. I was Indian citizen. My daughter is born in US. My wife is Singapore citizen, born in Singapore and on US Green Card. I am getting ready to apply for OCI for myself and my daughter. I was wondering if I can apply PIO for my wife at the same time together with my application. How much time would these applications take? What additional documents might I need? Is there any eligibility criteria that I need to check? I tried to call Houston several time with no luck. Any extra information that you can provide will be helpful.