I have a couple of names for you.
http://www.oakwood.com/cms/main-page-about-oakwood.html (503) 582-9229.
Execustay (503) 499-6625 or (206) 889-0866.
Relocation Coordinators (503) 684-5355.
These were the names in my book - I hope they're helpful to you.
Of course there are possibly options Craigslist.com, and with Ikea in town, you could furnish an apartment for very little, so if the executive stay places are too expensive, she might like to live in the Pearl District in a loft or apartment, which will feel more European, as you can walk everywhere, and I have resources for rentals there...
Are you in Portland Maine and she's coming to Portland OR?
Anything I can do to help, don't hesitate to contact me.