I don't think my mom will go for a trainer, and I have to use my money for my 3 horses,
Might be worth doing before you just dismiss the idea out of hand.
The stockdog trainer I used to work with was $15 dollars for a group lesson (only $10, actually, if you did only a single run on the sheep with your dog, and then an additional $5 for a second run) and $30 dollars for a single private lesson. It's not like we are talking about several hundred bucks here or something. Even if you could only arrange a single private lesson with a trainer, one could give you some tips and teach you proper handling techniques and proper forms of discipline to continue to work with Claire at home.
I can't imagine a difference of $30 dollars or so means taking food out of your horses mouths. If it does, there is obviously a much bigger issue here.