I'd recommend that you buy into a mobile home park near her and enjoy her when she's home. Don't get into a Del Webb-type community where the cost is high and you'll have additional monthly/yearly fees.
My parents currently live in a very nice DW community. We looked at a lot of them in our travels because that's where we thought we'd end up. We found new construction to be ridiculously overpriced. Resales in the same development were much more reasonable. In our area, we found it way, way cheaper to buy a lot with an old mobile on it, haul it & have a new one built. We previously built a custom home in arguably the two most prestigious areas in the Temecula area. Let me assure you, so far, construction quality of our new mobile is at least on par with our stick builts. Interestingly enough most of our new neighbors have similar stories. Once you have it, you find that it isn't that big house on the hill that makes you happy.