This is a grouping of ponies that may actually be from different lines as their markings are different. The original appears to be called Pretty Pony Club (a UK line) and are marked Just Group PLC. Others are marked M.I.G., and others (of cheaper quality) have a symbol I can’t identify on their hooves.
Adults marked Just Group 1995: approx. 3.75″ tall
Foal marked Just Group 1996: approx. 3″ tall
Foal marked 1996 M.I.G.: approx. 2.5″ tall
(this first one is just a TINY bit larger than the other two)
Sitting foal marked 1997 M.I.G.: approx. 1.5″ tall
Foal w/ Z? N? letter symbol on hoof: approx. 2.75″ tall
Foal with same symbol as above: approx. 2.33″ tall