Bonding Bonding adult female and young female, maybe getting along but not sure?

I've had my pig Penny for a little over a year now and finally found another young female a couple weeks ago, who I've named Pepper. Quarantine was over and I introduced them today. At first I was really pleased with how it was going. Penny was following her and popcorning and they just seemed pretty excited. They did good for about 20 minutes and then the teeth chattering and rumblestrutting started.
It never got to the point of needing to be separated but it was pretty stressful to watch. Pepper followed her around and a couple of times she took a chunk of Penny's fur, but I've always heard that if there isn't any blood or serious fighting to just let them sort it out so I just watched ready to break it up. They kept doing this for a while and as time went on they calmed down more and more. Penny would start squeaking when Pepper got close to her but after an hour or so she stopped trying to chase her as often and they mostly stood around eating hay but I could tell Penny still didn't want her being too close.
They eventually settled down and hadn't really bothered each other at all for about 30 minutes so I put them back in the (completely cleaned) cage. So far it's been fairly peaceful but a few minutes ago Pepper came into the loft and butted Penny in the nose and kicked her out of her favorite sleeping spot.
I'm still keeping an eye on them and I've yet to see any serious fighting but I'm still worried about them being in the same cage together. Is my fear unwarranted? Does this sound fairly normal or should I separate them? I've only ever had one experience trying to bond guinea pigs which didn't turn out good so I'm nervous about this but don't want to separate them unnecessarily and undo any progress.
It was also unexpected to me that the younger one ended up being the dominant one.