Horse & Pony Books:
(LOTHROP, LEE & SHEPARD [USA] 1965)
ILLUSTRATED BY HAROLD BERSON
Reprinted in hardback by original publisher.
SUMMARY: When the family move to the country, Tibby finds there is a horse installed in the stable that comes with their new home. Its owner begs them to keep the horse until the spring when it can be sold. Although Tibby at first knows nothing about horses, she soon falls in love with Warlord and is hoping she will be able to keep him for herself.
A DIFFERENT KIND OF SISTER
(LOTHROP, LEE & SHEPHARD [USA] 1968)
SUMMARY: Sally finds her dreams of a summer of riding marred by what people will think of her sister, a grown woman with the mind of a child.
Both easy to find in the USA. Harder elsewhere, although there may be one or two copies to be found on the internet in the UK.