Hey we're a system responding to that post you made, hope you don't mind that this is an ask. (We don't expect you to publish this, just offering some thoughts, feel free to respond or ask for more advice though). We've never been in quite the same situation as you so take this all with a grain of salt. (Also I'd like to note that this is directed at any/all of your system not just whoever reads it/made that post)
First up, having individual names won't necessarily take away from the body's name, but if it does end up doing that, why does it matter? If someone doesn't feel comfortable with their name and decides to change it that's completely fair, if someone finds another name they like and decides to use multiple that's fine, if someone uses different names at different times (e.g. online and offline names, some genderfluid folks, ect) that should be respected, it's no different for plural folks. Sometimes names change, and sometimes you have more than one, and either way that's not a problem. It's your name, not hers, why does she care if it changes or doesn't mean as much to you anymore? Maybe ask her why that idea bothers her and see if you can work on it together. (Also sidenote: there's every chance that you'll still feel comfortable with that name, your relationship with it might not even change much if at all, who knows. I know a lot of median folks tend to keep a reasonably close relationship with their (pre-system-discovery) name, maybe that'll be the case for you, maybe not, you're allowed to feel any way about it, that is not someone else's choice.)
On the second point, (the parasite thing), even though you have only just started understanding yourself/selves as plural, you did not just start existing. This is your whole system's body and life and it always has been, even if you didn't always know that you were a system. Having individual names would not change that in any way. I'm going to be honest, I don't really understand your girlfriend's perspective on this point. Mostly I'd just suggest asking her about it. (Maybe try explaining that your system isn't a new add-on to your self/existence but rather just, who you've always been? I don't know if that would help here because again, I don't really understand her perspective, but it might be worth a shot.)
Hope you work things out together and that this helps somehow. Either way good luck with the early days of system awareness, I know they can be rough sometimes but it does get easier.
I feel pretty bad cause I haven't checked my inbox like... ever, but nevertheless, thank you so much for these words, they mean a lot. She and I are no longer a thing, but after the fact I did realize she didn't care enough to consider my world on it.
She went off on me atleast twice about how it was hard on her, and how she couldn't just understand overnight so I shouldn't talk about it for a while. I realize now she just didn't want me to change. We've gotten to know ourselves better any we all have names of our own, but collectively use the body's name. She had such an issue cause we already changed our name 2-ish years ago, and she couldn't understand. She hates her name, but doesn't want to change it cause "that'll ruin my relationship with my family, cause I'll have to tell them" Her family sucks.
Either way, thank you so much for these kind words, Anon, I hope you have a wonderful week.
Sorry it took me so long to get back to you...