Overcame fear, now just STUBBORN!

Trailer Loading update:

I was able to load Pippi into the trailer twice, using feed and positive reinforcement. And then Pippi decided to change her tactics. Her entire body language changed, and it became clear to me (and to my daughter) that she was no longer afraid of the trailer, she just did not want to enter it. The reward was not interesting enough unless she was totally starving. Well, that changed everything. It is not as though we can always starve Pippi each time we want to trailer her, so our tactics had to change.
Now, like I have stated before; beating her onto the trailer is NOT an option. But intimidating her onto it, Heck yes!! Pippi is very stubborn, very very stubborn. When she puts the brakes on, they are on, and no carrot, treat or hay will  entice her to move a muscle. She never becomes aggressive, and so is not dangerous, but she is willing to stand motionless forever to get her way. She is a statue, and just will not move a muscle.
So, it was time for my daughter, the 19 year old Pippi trainer and my trainer, to take over. I had no dea what her plan was, and since I baby Pippi to death, it was better that I did not know. On Thursday at nine am, my daughter, who is on spring break, called, and stated with a great amount of pride: "we are on the trailer."
This is what she did, and quite frankly I think it is pretty clever:
She used the long lunge line with the chain, as a lead line (so the chain was not over Pippi's nose) and asked Pippi to enter the trailer, stupidly Pippi refused twice (even with the treats and incentive). So the chain was put over her nose, thru the halter, which Pippi knows means BUSINESS! We hardly ever use the chain, deliberately, so that Pippi knows that when it comes out, we are not playing around anymore. Daughter then threaded the end of the lunge line thru one of the tie rings at the front of the trailer, walked behind the stubborn mare, and looped the line around her butt. Then she asked Pippi to "walk up," which Pippi refused. So daughter pulled gently on the rope, which simultaneously pulled Pippi head towards the inside of the trailer and pushed her rear forward. Pippi felt that backing up was not an option with the rope behind her, and so she walked into the trailer. She was given a hay bag, and her feed as a reward. And daughter brushed her and massaged her while they stood in the trailer.
Not at any point did Pippi act distraught, she just kind of gave up the fight. That evening we did the same routine together, and  fed Pippi her dinner in the trailer. The next day Pippi walked in the moment the chain was placed over her muzzle, no need for any other sign, she got it and walked in as though she was entering her stall.
I asked daughter if she had seen this done before, and she said she had seen it done with one person pulling on a lead line and two people using a rope behind the horse. She had seen the rings inside the trailer, and decided that using those she could totally do all the parts alone. With a lot of people, more than the two of us, Pippi seems to get worked up, when she is uncomfortable. She loves people, and especially little kids, and cats, but when she is stressed she gets more obstinate with each human that comes around. The talking and discussing and all the hands touching her, pushing on her, looking at her, makes her sink into herself and she just sort of disappears. The manager where we board, won my heart when she told me that she was worried about Pippi one day, because she was not herself and that she felt that Pippi was "robotic." (It turned out that Pippi was getting sick and not tolerating her feed, but the physical signs of that was not yet apparent). I have tried to explain this personality trait to people, with some odd looks, so it was great to have someone know and "see" my horse.
My daughter was able to control Pippi, with no force, and to do it alone so that Pippi was as comfortable as possible. The trailer has left now, but our friends will bring it back in a week, so that we can practice again. Good on you daughter, and Pippi too.