In this case it's probably "of them", but you wouldn't guess without context: "La mia ragazza ama il calcio" "Ne conosco qualcuna così" ("My girlfriend loves football" "I know some [girls] like that"). "Qualcuna" isn't singular because it's the contraction of qualche+una (compare some+one = someone): "qualche" always needs a singular after it, but the meaning is some, a few.
Actually, "qualcuna sa che ora è?" would be extremely rare in Italian; the masculine is used even when addressing a group of girls, unless there's a partitive, like "qualcuna di voi", or the "ne" in this sentence. In such cases, though, you'd say "some of you" or "some of them", rather than "someone of you" and "someone of them", right? If the sentence had been "Io conosco qualcuna così" (although "Io conosco qualcuno così" would be much more common, even when speaking of a woman), the translation would have been "I know someone like that".
The one correlating with "non" (or with itself) to form "neither/nor" is né (ni in French as you're studying it): ne (en in French) instead is a clitic pronoun with a number of uses. Typically, it's a partitive (of it, of them), but sometimes it can express departure (i.e. from there) and sometimes it just forms pronominal verbs, i.e. it forms a new verb meaning. In English you don't always specify, e.g. "I have one" implies "of X": in Italian you have to (e.g. "ne ho uno").
This helped me tremendously - https://www.thoughtco.com/using-ne-in-italian-4074179