In the chapter 482, Neinhart started to realize that he has heard the name Erza before, nonetheless, he knows that she is the Erza Scarlet that he has heard of. He started figuring out that there might be some connection between Lady Eileen and Erza scarlet.
“Hair…and this magic power…”
SO I want to ask are those two really related?
Yeah, there is a hint that they might be related. The guy on the pic sees similarities between the two (both are way too scary not to be related, lol) and then we see that Eileen is red-haired. Naturally we all think, 'Oh wow, Erza's mom is badass' but it should be confirmed soon in the next several chapters.
The anime/manga itself hasn't confirmed it, so technically they currently are not related and the idea of them being related is a theory (doesn't mean its wrong). If the anime/manga DOES confirm it, then yes, they are related.
You have already linked the entirety of the evidence for and against their relationship. As of right now in the manga, it is Hinted that they are related, but nothing has actually been said. There does seem to be a resemblance between Eleen and Erza, the power and hair, as well as looks, but that one panel you linked where Neinhart noted these things is all we have to go on. So until we dredge further into the manga, we will not get any answers to that question. I would fully expect for it to be true, but we are pretty much guaranteed to find out if it is or not eventually.
Maybe Eileen IS Erza, in fact the future Erza. Look at the scar she has: it's like the injuries Erza has in her battle against her Historia. More, in the current chapter (489), Eileen says it's a magic form "the new era"! With the Eclipse Gate, time travel is certified possible in FT...
Personally I think that Eileen is either Erza's mom or like, Erza from the future or something. The reason I think she is Erza's mom is because of the few hints that they are related here and there in the manga. Some of you reading this might say that this is not possible since Erza and Eileen don't have the same name. The fact is we don't know if this is true or not. Your response might be saying that it is because Erza's last name is Scarlet and Eileen's last name is Bersilion. Well Scarlet is not Erza's real last name. If you didn't skip or if you remember in previous chapters of the manga/ previous episodes of the anime you will know that when Erza was enslaved and were with Jellal, Simon and the others she introduced herself as just Erza. Jellal is the one who gave a Erza her last name when she was a child. The reason I think that she is Erza from the future is because in the end of chapter 507 it ends with Eileen saying to Erza "I am you and you are me" But I am more for the Eileen being Erza's mom. These are just my personal theories, more likely than not we will know the answer in upcoming chapters but for now we have to wait for these chapters to be released,
