1988:
SWEET DREAMS CRIB
As the name suggests, this was a playset on a smaller scale, issued to help take care of the large number of baby ponies that now populated the UK market.
The crib featured a pillow, blanket and even a mobile to help baby get to sleep. It was not sold with any ponies, though the box suggests that both Baby and Newborn ponies might like to use it! In the UK, the box featured Newborn pony Shaggy. It also sometimes came with a mail offer leaflet (pictured) which had valid offers up until Easter 1989, suggesting it was released right at the beginning of 1989.
There is a variation with some of the accessories for this set. The box art pictures a pale blue stand for the mobile, but the insert (shown below) pictures a yellow one. This is not just artistic licence, as both exist.
VARIATIONS on the MOBILE STAND
The UK box also states that the playset was made in Spain, a common feature of playsets during this year and in subsequent ones.
The above image is taken from the 1988/9 insert, which seems to be the only one that features it. Though it was termed "Pony Crib" on the insert, the playset itself in stores had the same name as the North American release, which was "Sweet Dreams Crib". The box dates the playset to 1989 in its UK release.