Your mare needs to know who is boss. Some horses learn it, some have to be taught. Ground training is like a key to a safe, if you have the right kind it will work, and without any key you will be getting nowhere fast. Think like a horse. Think:
"In the wild, how does a horse show dominance?"
Sadly, horses show dominance by kicking and squealing, biting, etc. If we humans contend with THAT we will get hurt. Lunging is like a fight. (Like I said, depending on which horse you are dealing with) You are the leader, you are managing to keep control, they learn, and will show subjection. Whips are great. The sound of a cracking whip and sometimes certain noises can make her think
" She is boss"
Be consistent. If this does not work, try something else! But most important, get to know your mare. Everything I said may work perfectly for some, for you it may not work the least bit. And if she is unruly in the saddle, try some equine tranquilezers to calm her down. Hope this helps.
DG is right! Like I said,if you think my method is wrong, maybe that is because it will not work on your horse. Let's all share our ideas, and let her mare decide which works best for her.