I know this name was used and apprently made up for the [name]Lord[/name] of the Rings movies but I’ve never watched them and have only heard it used “in real life”. I found out the connection with the movies when I looked up the meaning of the name, which is “horse lover”. Being that I grew up with horses and they are something I shared with both my mom and grandpa (the two people I’ve been searching for names to use in honor of) and I love the spelling, sound and possible nicknames, it seems to be pretty much perfect. The connection itself doesn’t bother me but it seems to bother other people… your thoughts?
I think most people will either have no idea how to pronounce it, or will immediately think of [name]Lord[/name] of the Rings. It’s a pretty name, though.
[name]Philippa[/name] means horse lover, too, if you like that. Cute nicknames like [name]Pip[/name]/[name]Pippa[/name]. I’ve also heard that [name]Rhiannon[/name] (slightly more exotic and along the lines of [name]Eowyn[/name]) is loosely connected/associated with a horse goddess.
I think the bigger problem is pronunciation,and I personally dont think [name]Lord[/name] of the Rings is a bad appeal. I love the meaning and it’s personal connection with horses, and I agree with the pp suggestion of [name]Phillipa[/name] which is eaiser to pronounce. I still say go for [name]Eowyn[/name] though if you like it, it’s a nice name.
[name]Just[/name] for fun I’ve looked up some other girl names that mean horse or have to do with horses, mabey there’ll be a winner. 
[name]Agrippa[/name]-wild horse (Russian)
[name]Agrippine[/name]-wild horse (French)
Amethea- one of the horses of the sun god [name]Helios[/name].
[name]Rosamund[/name]- horse-protection
[name]Rhiannon[/name]-Welsh horse goddess
[name]Derby[/name]-after the race, might be cute
[name]Penelope[/name]- you can get the nickname Pony out of it
HTH!
I think [name]Eowyn[/name] is very pretty and very feminine! I don’t mind the association and when I see this name, there’s only one pronunciation that pops into my mind… Go for it 
I have no idea how to pronounce this sorry :S And unfortunately that may well be the reaction many people have. I like the sentiment behind it though.
Rhiannon - Wikipedia - I love [name]Rhiannon[/name], according to Wiki she was compared to the horse goddess Epona of [name]Gallo[/name]-[name]Roman[/name] religion, so that’s another name option though a little “out-there”. Could also give you Pony as a nn!
Good luck 
To go slightly off-topic: There’s a book by PC Cast called ‘Divine by Mistake’ about the goddess of [name]Partholon[/name]. The [name]Goddess[/name]’ name is [name]Rhiannon[/name], her horse name is Epona (Epi for short).
I don’t like [name]Rhiannon[/name], but I do like Epona/Epi. I still prefer [name]Eowyn[/name] however 
[name]Eowyn[/name] (ah-oh-win) is a very pretty name but most people would not only have trouble pronouncing it but spelling it as well. But if you like it, go for it!