Horse let's others ride, but not me

Hey!
I'm working on a horse that hasn't really been handled, and she's 15. Basically she lives in the spanish campo with her sis, and I've decided to start her.. anyway, she's doing great and so on.
But here's the problem. I've got someone to lay/sit on her these first times, and she's now fine with people (any one.. except me, but we'll get 2 that), I mean as in a person can basically just jump up on her back, as long as I'm in front of her! So, here's the thing! She wont let me ride her:S She gets real weird n so on when she can't see me and someone tries to get on her, and she gets even weirder if I'm just on her back.. I mean:S what's going on??
I'm not nervous at all, so I'm not sending any bad vibrations or you know. I kind of know what I'm doing, but this hasn't really occurred before!

It sounds like she's kind of attached to you.

My horse was a bit like that. What helped alot was talking to her. She knew my voice and it reasured her when I just kept a monolog going the hole time when I rode. After a few rides she understood that it was just me up there and she wasn't alone. Also I had somebody longe me. So somebody else on the ground, wich might also help give her a bit more confidence.
I do think it's kind of strange that this horse got so attached to you in such a short time. I was the only one who has ever handeld my horse and she's very much a "one-person-horse" She isn't very attached to other horses either... If your horse is, it might also calm her down if there is another horse in the ring (a calm horse). Or just a diffrent person on the ground. Maybe she just needs a bit of help in the beginning. Everythings new and so on...
Well I hope you find a solution! :)

You need to stop to be allways in front of her.
You need to find another person that will do the job you are doing now, so you can start going on her.
Let some one else lunge her, be in the ring aswell. Move away or something,
You also have to start to shy her a little bit away from you. She won't fully respect you until you have got her the understanding that this behaviour, not letting you riding her is not what you are looking for (eh guess you won't hit your horse and I'm NOT telling you too do that)
More like, if she is stepping to close to you, put your hands a little in the air, and show her that there is a circle around you that she should not be entering. If she listens, and follow your order then of corse be nice to her and then you in charge let her come closer to you.

How about no one stands in front of her while your riding?
Get her used to it. Talk to her, reassure her, let her know your there. Take it easy for the first few days.

One, teach the horse to allow people to mount it alone. I break babies alone... no one holds their face for me. You just have to make sure her head is turned to the side so she can't take off if she does get scared.
Two, it sounds like a typical baby, so no worries. :) When they see you on the ground all the time, they get 'confused' when you're on their back--they can hear you, but they can't really see you! You just have to move on like nothing's different... hopefully, if you learn to mount alone, this problem might go away.
Good luck! Babies are fun.

The youngsters I worked with usually had the intelligence to know that when I jump onto them, I am on their back and did not acted like that. I think average horses can see the connection between that you stand in front of her, than you stand beside her then you sit on her... She should have know tht you are on her!

Check if she is not dumb. You wrote she gets frightened when she cannot sees you. Can she recognize you only by your voice?

I agree with daroczy. Horses generally are NOT dumb and know who is on their back. My paint used to turn her head and double check it's ME on her back and not someone else (not anymore though). Can people actually RIDE her or they just get on and sit while you hold her?

hmm oh well my words didn't get out to well,

I was more like takling about
While you are getting on (get on and off) so she will get used to you doing that,
Then let some person stand it front of her.
She might think that having a person in front of her is saver, some hroses think that, in early training.
Then let the other person move away of corse

Haha, I wasn't suggesting she was dumb. Many of the 60/odd colts at our university acted in an 'omg where did you go?!' way. For us... of course it's logical, we went up on their back. All they know is you disappeared.. and now something's on them!
Ah, prey animals.