I wouldn't do it...
The PHE II is one of the few Raritan products I don't like. Adding a motor to the PH II only replaces the pump handle...it's still a manual toilet, you just get to push a button instead of pumping it manually. That part's ok. The part I don't like is that the motor pumps the the toilet a lot faster and with a much shorter stroke than pumping manually, which means that the pump takes longer to prime--wearing out seals and o-rings much faster, which results in the need for more frequent rebuilds--and also means that the toilet can "choke" on flushes that manually flushing slowly and deliberately would push through. It also draws more amperage than most electric macerating toilets. In short, IMO adding a motor to a PH II turns an outstanding manual toilet into a poor excuse for an electric toilet. The only advantage to it over an electric macerating toilet is that it can be converted to manual again in an electrical emergency...otoh, if you don't have enough power to flush the toilet, flushing the toilet is the least of your problems. If the admiral wants "push button convenience," I'd go with the Raritan SeaEra conversion. It's a true macerating electric toilet, and is available in both raw water flush and pressurized fresh water flush models. She'll love it! Check it out on the Raritan site at http://www.raritaneng.com And if you really want to make her day AND yours, consider adding a Lectra/San (Type I MSD that treats waste and discharges it overboard...legal on the Bay) to the system too. You can check it out while you're on the Raritan site.
