We've decided Kate's first words are officially "cheese" and "shoes."
It's been hard to know what "counts" as an actual word. She has said "Mama" and "Dada" for several months, but they are not reliably attached to Matt and I as people, so we don't totally count that. She has said "peece?" (please) a few times, but not consistently, and she says "Ala?" (hello) when she is pretending to talk on a phone, but seems to assume that's only something you say on the phone and not in ordinary in-person greetings.
Anyway, last night Matt was trying to get her to eat some Asian shrimp and veggies over couscous (what we ate), but she kept asking for cheese instead, over and over. Finally, when it seemed she was not going to try our dinner, I pulled out a string cheese--her favorite. She saw me holding it, and just lit up, smiling and pointing and saying "cheese!" So we decided that constituted a clear connection between object and word. She does that with shoes too, so I'd say they are both her first words.
She says "cheese" at the end of this video we shot last night. Pardon the darkness and the fact that for the first half of the video, I'm trying to get her to make her monkey noise as she played with her Animal Train toy (which I purchased over a year ago at a consignment sale and just pulled out, so it is "new" to her).