1987: So Soft Ponies
TWILIGHT
Purple pegasus pony with pale pink mane and tail, candle in holder symbol. FLOCKED.
Here beginneth the name repetition plague of 1980s ponyland.
Okay, so I'm a touch melodramatic, but So Soft Twilight was probably the earliest pony to recycle an older pony name. This would be a classic theme of the My Little Pony line in North America over the years - there were two Twilights, two Sniffles' and Snookums''s, three Sea Breezes and multiple ponies with the name Cuddles. Even the UK didn't escape the name plague - though to my memory there are only two occasions of name repetition in the UK line.
Whatever the reason - whether a breakdown in the already-used-name communication department or whether deliberately linking older ponies with newer ones, we won't probably ever know. But So Soft Twilight bore little resemblance to her Unicorn cousin. She was the only pony from her set to feature in the animated series - in the episode with Cloud Castle. She was also used on some promotional material - even in the UK - to advertise various accessories.
Twilight was never sold in any other set or without the So Soft flocking. She was also never sold in the UK. Her pale pink hair can fade out to white easily - this is not a variation, but sun damage.