@zStella the same lines have different meanings in different contexts. Doubly so in japanese.
I'm 99% sure the sentence has no subject in the raw (I haven't been able to check it yet), therefore in chapter 3.3 she's saying "(I) have no friends", while in this chapter she's saying "(she) has no friends"
(It's the same line because it's the pot calling the kettle black)
edit: I couldn't find raws for the manga, but I found the rough equivalent on the webnovel. On the end of chapter 12, we get these lines:
「ふむ……単刀直入に言うと、私は彼女の秘密を知っているわ」
「秘密?」
「レーラ=サカグチ……実は彼女――」「――友達がいないのよ」
the first two lines are the equivalend to the two speech bubbles at the end of chapter 3.4
the next line is cut by description on the wn, while in the manga I think the first part is actually still in chapter 3.4, while the second part is the first line of chapter 3.5
In isolation, 友達がいないのよ can mean either "
I have no friends" or "
(the subject) has no friends".
While,
in isolation, the former meaning would be the most correct, here it's clearly the latter