I decided to get on Tilly and see how she was under saddle.
The saddle fit nicely and I chose a bit-less bridle. Tilly was calm throughout tacking her up and getting on her back. One hiccup….she would not respond to my leg or move forward at all. My friend decided to lead her and Tilly walked easily forward. I decided to end with that for the day. A few days later I got on her back again. Same thing happened- she would just stand there. Small spurs, leg, a crop (which I hit gently against my leg)…none of them worked. I was frustrated despite it not being my sweet girl’s fault so I ended our ride. I knew nothing could be accomplished with me being frustrated. I decided to do some research on work horses and posted on some Facebook forums about my situation. I received some awesome advice!
The advice I received is below.
“If she was used in harness you will probably have to use driving commands as you teach her.Walk on, or get up to go forward. Gee to turn right, Ha to turn left. May have to tap her hind quarter with the crop.”
“Get someone to lead her after you give her forward cues”
“She may never have been ridden, on driven. I would find a good trainer who works with starting horses, even though she’s not young. It will take months but if she’s started correctly she’ll be lovely and at her age will help to keep her sound once she begins to WTC, as driving horses only walk.”
“Probably a driving horse. Try “Step up” or “walk on” look up the Amish terms. Gee, Haw, Gee around, Haw around, etc…See if that helps. If she was a driving or plow horse it also helps to hold your hands wider at first.”
“Patients little at a time he or she needs to know you love them first ground work is good he may be sore see if he’s stiff arthritis meds or joint supplements he may only know driving commands such a gee or has or come and get good luck”.
“Sounds like she hasn’t been ridden but is a good girl! She may need a bit in her mouth to understand what you are asking since she was driven. If she understands words, perhaps say them for what you want. Looks like others know those words better than me! I know my horse that logged has a nice “whoa”. Just can’t say “good boy” – sure, sounds like whoa! I saddled and sat on a driving horse, Belgian (no history known) with a leader for walk only. I felt that he was sore – even though there was no outward sign – perhaps the way he held himself. Not saying this is the case for you – just a thought. I like the other advice here as well!”
“I rescued my 18 year old boy in November 
Same history as your mare. As workhorses, they were not trained to ride, and they don’t know the commands or how to respond to leg pressure or the bit (other than pulling). So you need to start with groundwork and then at the very beginning, because basically they are green. I do not use a crop on my boy. Never will.”
“I would never give her spur or crop. You don’t want to punish her for not understanding your cues.”
“My Belgian was not broke either but she did walk out just fine unlike your mare. Get a driving bit…that’s what she’ll be familiar with. Check all voice commands to see if she knows any of them. If not I’d teach her voice commands lunging her and then get back on once she’s responding well.”
“Because they came from Amish, a friend told me to learn the commands in that specific language (version of German). Worth a try. BUT, I will say, I have tried to avoid anything that would remind my boy of his previous owner.”
“Haw & Gee. These are commands used to ask what direction to turn by the horse by voice command. It works well when they’re in harness working. Gee means go right, haw means go left. The Amish use “step up” to take a step or two forward and “ walk on” to walk. “Whoa” to stop. Try these commands while mounted. Slowly add in the ques you want to use in addition to the verbal ques your mare already knows.”
“She might have never been used alone, which could mean she’s looking for a cue from someone else, (it would explain why someone needs to lead her) amish usually use a oring bit, she might do better with blinders at first, and she’s probably voice activated. She won’t have any clue about leg cues. Start ground driving her, she still might be a little confused being single but she figure it out. good luck.”
” when you are on her wanting her to go sometimes turning her to one side or the other where she has to step to move is a good way to start her momentum.”
The Chances We Take 