She has kids? Well that must be a genetic first
If I were doing it, I would take the piglets well away from her for a couple of weeks, then introduce the two groups together. She needs to see all the little blighters as strangers. Two weeks should do it.
There is bound to be some scrapping, but if you have a big enough area for them to escape into, they will be able to move a lot faster than her and get out of her way.