Thanks, Phizzy, good ideas. Lucy's getting her teeth done next week, and will have an adjustment by the chiropractor at the end of the month. At this point trainer thinks she's doing this because she's gotten away with it for a long time, and also because she's out of shape and can't hold a frame that well. Plus, she's been in this barn only a month, I just started riding her last week, so she's got some settling in/down to do.
During today's ride I noticed that she'd raise her head when we were working on patience while under saddle, you know, getting her to stand still and chill. Whenever I shifted my weight in the saddle, up went the head. Trainer is going to work on getting Lucy to just mellow out, once she's able to ride again.
I tried Countrymouse's suggestion and spent several minutes correcting/making her work when she raised her head as I tried to dismount. She finally figured out what she was supposed to do and kept her head at an acceptable level during the dismount. Will continue this routine 'til the head stays down!
Mary