Well, I don't know Voodoo or proper Voodoo counterspells. For that kind of help you're probably going to have to contact a professional Voodoo person and pay thru the nose to raise sufficient interest in him or her to make this his or her business.
As a few stopgap measures, here's a some things you can try.
- Get some of your Mom's hair, an item of jewelry, and a picture. Put these things together and, while touching them to her, have some Energy (Aetheric would be best, but Prana will do) flow thru her and into the things, making them be as one. Then put the group of things that now are one with your Mom into a 1+ gallon container of rock-salt mixed with table salt. Salt has a tendency to make magickal processes cease working, so the only problem with all of this is that when it starts working as a magickal process, you'll know it because while it will make all of the other magickal processes focused on your Mother stop, it will also make itself stop,, so you'll need to re-do it, probably daily, and/or teach your Mom to do it herself;
- Gather whatever you need to be able to focus on the person who is causing all of this. Make the space sacred in whatever way you know and are most comfortable with. Focus on the person, and as you have experienced a bunch of the negative results of her presence and activity in the world, know that it is likely that many others have done the same. Using that awareness, imagine everything in the world that challenges her or opposes her, or frustrates her or limits her or restrains her. Turn your focus to all of those {people/things/phenomena}, and intensely bless them with great positivity, energy, motivation, strength, power, vitality, health, joy, love, life, and every blessing that you can imagine;
- Go to a powerful diviner and find out which spirits or Deities you should involve in this to counteract the negative entities she is sending, then research the rituals to contact/ evoke them, do so, and make agreements of alliance with them;
I hope that helps!
Biggest Brightest Blessings!!!