I agree that you should slow it down for a bit. You can keep things short, and loung her for a bit and let her get used to doing that and trusting you. You may even try joining up with her if you have access to a non-flooded round pen. (The one at my barn floods after heavy rain, haha). I have been working with a 12 y/o OTTB at my barn that I wanted to jump so I've learned a few things that may help you. First:
1) Keep lounging her on the line for a few weeks, even if she seems to be doing ok now, don't rush her. Keep reinforcing that she is being a good girl and doing it right. (Remember to keep the "right thing comfortable, wrong thing uncomfortable" mentality).
2) Lounging aside, to get her used to going over poles now, continue to hand walk her over ground poles as a separate lesson from lounging. This will help to let her know poles are not scary and she has no problem picking her feet up just a bit higher to walk over them. The important thing to remember right now is to keep these two lessons separate.
3) Assuming she continues with what sounds like amazing progress, based on what you've said, then next combine the two. First use only one single ground pole. If you are working in an arena (as opposed to a round pen), place the pole directly in her path. For example, if you work her along side the arena wall (as opposed to the middle), then place the pole on the wall, directly where she is forced to step over it. Start at the walk and then work your way up the gaits.
4) If she handles this well, you can raise the pole on blocks to have it be only a few inches off the ground. If you have jumping blocks, lay them flat on their sides. If you are using standards instead, I would put it on the lowest hole, or find some other means of proping the pole up only 2-3". Again start at the walk and work up. Remember to still place the "jump" in her path so she cannot decide to avoid it. If she gets scared and tried going around, use the whip to direct her back and slow down back to the walk.
5) If this goes well, you can make an X. I would still keep it very, very small. Less than 18", even. Maybe prop the jumping blocks on their side and use two poles to make an X. Still keeping the jump in her path, place two more poles as a "runway" to the jump, forcing her to go forward. /X\ <---- Like that. The two poles are both on the same side of the jump, one before, and one after. It is to help direct her over and to keep her from dodging out. It can be high or low, depending on what scares her or how much she dodges. Eventually you can take these runway poles away and let her just go over the jump. If she knocks the jump over at any point, that is ok. The OTTB I was working with literally plowed through it. I was worried he injured himself, but the next go-round he completely over jumped it. It ended up being a good thing because he learned jumping INTO the jump and knocking it down is not nearly as much fun as simply going over it.
Hopefully that helps! Best of luck!!
~He knows when you're happy
~He knows when you're comfortable
~And he always knows when you have carrots.