Home on Folly Farm by Jane Lovering

Needing an escape, Dora swapped city living for life as a shepherdess on her grandad’s Yorkshire farm. More than a decade later Dora is still there, now farming the fifty acres and caring for the one hundred rare sheep by herself. She never hears the call of the city, but instead relishes the peace and simplicity of life on the Moors.
When Dora’s glamorous but quarrelsome sister Cass, her teenage nephew Thor and his handsome tutor Nat, turn up for an unexpected and unreasonably long stay, life on the farm is thrown into chaos. Cass brings with her unwelcome memories from the past, and of someone who once stole Dora’s heart.
Dora takes refuge in the comforting routine of the farm, the sheep never allowing her too much time to dwell. But, as the seasons change, the snow starts to melt, and as lambs begin to fill the fields, Dora can’t keep hiding in the hills. Because even though she’s trying, Dora can’t run away from a love that never really let her go…