I think Sinaloa is stretching it to far. Baja, Sonora, and Chihuahua is a bit more doable.
I don't think the US was interested in puppeting parts of Mexico. If they wanted control over the territory, the US would have just directly annexed it.
But again, wanting and annexing are too very different things. Annexation required a treaty through congress. Getting a treaty from the Mexican congress was anything but a sure thing. Look at how difficult (and when you see how the parties responsible made it happen), lucky really, to get the OTL treaty through. I think adding anything additional goes a long way in the congress basically means the existing congress under occupation in the capital only go underground and wait out the occupation forces and war expenses to force out the Americans. Without a treaty, no annexation. A divided US congress is not going to just push through a fake piece of paper either.