The Border Vixen by Bertrice Small

Dugald Kerr, the laird of Brae Aisir, has lost his male heirs in the raging border wars. He has but one inheritor remaining: a beautiful headstrong graddaughter known as Mad Maggie. There are many eager to wed Maggie, for with her comes the profitable right to exact tolls at a famous safe passage through the border hills, which has been under the protection of the Kerrs for generations.

Keenly aware of the covetous interest in his lands, the laird announces that any man who can outrun, outride, and outfight Mad Maggie will win her and her inheritance. His proposition causes more chaos than resolution, for feisty Maggie's reputation precedes her, and the one man to take up the challenge is roundly defeated.

But young King James V learns of the laird's problem and dispatches his cousin Fingal Stewart into the borders to wed the heiress without delay so that the valuable pass may be protected. But the laird insists his conditions be met, and the heated contest of wills between Fin and Maggie brings out the fire in them both. But there are those who will stop at nothing to gain control of Maggie's inheritance - even if it means getting rid of Fingal Stewart, and his border vixen.

This book is part of the "The Border Chronicles" series.
Here are some other books from this series: