i haven't read the censored version in jjwxc, but i'm assuming their ages were omitted in that chapter considering jjwxc's many censorship standards. this was the line from the raw of chapter 6, from the now deleted po18 version, also which the translator follows.
蓝妩重复了一遍:“你多大了?”
季泠月呆了一会儿,哑声道:“十,十四了。”
十四,人类十四岁算小吗?
it clearly states 14 here.
haha i appreciate dragontl and their other translations, but as they shared in one dc server they apparently made that intentional change since the novel's reputation (intl) is already poor with the noncon as seen in its NU reviews, what more with the underage stuff.
#-.-) still they should've added a note, i'm actually surprised no one had asked on their website yet, but if anyone would ask i'm sure dragontl would answer truthfully.
if you guys want to verify the source yourselves just search 入海 po18 for the uncensored chapter 6 raw, probably some sketchy

she was 18 years old in the novel, why make her 14 here? also the mermaid was almost 200 years old so gorl wdym you're not mature enough