A woman inherits an island that she had wanted to buy as a child

I read this book 20+ years ago. I was a teen then and had limited means of getting my hands on books, so I read anything and everything.

What I do recall is that the main character was a woman who'd had some sort of money or estate. As a young child, she had tried to use it to buy an island property at auction, but was unabled to. She was accompanied by an adult, but not her parent (making me think she was likely an orphan??). The island likely had a house on it, and at low tide could be reached by a land bridge.

Some other person won it, and left it to her after his death.

I honestly have no idea what the actual plot of the book was. Based on what I would have had access to, this would have likely been a Christian romance. But could have been a cozy mystery type novel instead.