Hi Landa welcome to the site. A lot of what you've said sounds similar to a situation I was in, multiple dating sites etc. same thing when I busted her she deleted the account. Also saving and buying land for our future togetherMore like a case of she picks the land I buy it and build the house I reckon. In fact, i'm wondering if it's the same girl
they're the same age.
Anyway, I had all those doubts, but when we were together things seemed wonderful, so I chose to ignore them. In the end it turned out I was just one of many bfs. I hope your situation is different, and like Forge says theres every chance she was just keeping her options open until she knew you were 100% committed.
But you know the saying? If in doubt don't.