I used to collect model horses, but i can assure you there are many, many model horse collectors that are adults, actually most of the serious ones are adults! Schliechs are nice, but there are nicer makes of model horses if you are willing to pay more for them
We have a collection of horses and farm animals. Got quite a few second hand from ebay (with tags still attached!) and now ask for them as small gifts at christmas and birthdays. We also use our local model shop as a day out because their displays are lovely for the kids to see, and then if (big if) they are good or have pocket money the kids choose an animal to add to the collection. We've got a very diverse farm so far!
Last trip to the model shop we bought a tack and rider set for one of the horses. I definately had more fun with that than my little girl Just want a dressage ring, a few jumps, the stable set, horsebox and trailer...etc...etc...
*Like!*
I did collect Breyers - got a few as a child and continued into my teens, but sold my collection as I needed money for the real horse!! I do plan to start again when it's more affordable though with custom models of my own horses
My 12 year old daughter collects them and spends ALL day in her bedroom making headcollars, saddles, bridles, rugs, boots and anything else she can make for them.
All of her horses have stable names and show names...she absolutely loves it.
She has also found a collection for friends on the internet and they all chat about their horses and post videos and photos...there is a right old club going on out there