Honestly, I'm not sure there's much you can do to "discourage" Pansy from giving Jack a little swipe now and again. Maybe there are some things you could do to get her to associate Jack with positive things? Perhaps giving her a special treat when he's near her, or giving her a good pet or brushing so she associates him with all those nice things?
It's also possible she's just determined to be the "top" animal, which isn't really a problem--there's going to be one dominant animal and one not so dominant in a two animal household--and its actually better that it is Pansy since she can't inflict as much damage to Jack as he could to her in the heat of battle. If no one is getting hurt in their little squabbles, then you're doing ok.
Our Emma has decided to be top cat in our house, which was sort of surprising to us since she is so much smaller than our cat Oliver (her 6 lbs to his 13) and Oliver was with us for 3 and a half years before we got Emma. She's just got a little more spunk in her than he does--probably because she was a "street fighter" for Lord knows how long, and Oliver has been a spoiled rotten prissy little Mama's Boy kitty since he was 4 weeks old!
Just try to keep an eye on them to make sure Jack doesn't decide to "strike back" one of these days, because that could get ugly. Definitely keep them apart when you are not home, or not within eyesight of them.
Good luck! I keep scrolling back to Pansy's picture because she has such a lovely face!