Fourfold Fate by Helen J. Fleck

Solene Whitfield doesn't want his money. She wants the deed to her mother's lighthouse inn, in writing, with no strings attached — and no boardroom is going to decide what happens to it next. Weston Ashworth has sixty days to marry or lose everything his family built to a cousin who'll sell it for parts. Neither of them wants the deal they're about to sign. They want each other even less. Six months. One signature. Zero feelings — that's the arrangement, until an ultrasound turns "temporary" into a word neither of them can use anymore. Now a future neither of them planned is tying them together for good, and the contract that was supposed to protect everything might be the very thing that unravels it — unless Weston finally chooses honesty over control, and Solene decides her mother's legacy was always meant to hold more than a building. Some arrangements are just paperwork. This one is fate — and it isn't asking permission.